Apparatus and method for performing quantum key exchange having basis independence in wireless communication system

Abstract

The objective of the present disclosure is to perform a quantum key exchange having basis independence in a wireless communication system. This method comprises steps in which a first device: performs an access procedure with a second device; establishes a connection with the second device; transmits capability information to the second device; establishes at least one quantum channel with the second device; and performs the quantum key exchange by using the at least one quantum channel, wherein the quantum key exchange can be performed using a transmit basis and a measurement basis that are different from each other.

Description

Device and method for performing a quantum key exchange having ground independence in a wireless communication system

[0001] The following description relates to a wireless communication system and concerns an apparatus and method for performing a quantum key exchange having basis independence in a wireless communication system.

[0002] Wireless access systems are being widely deployed to provide various types of communication services, such as voice and data. Generally, a wireless access system is a multiple access system capable of supporting communication with multiple users by sharing available system resources (bandwidth, transmission power, etc.). Examples of multiple access systems include CDMA (code division multiple access), FDMA (frequency division multiple access), TDMA (time division multiple access), OFDMA (orthogonal frequency division multiple access), and SC-FDMA (single carrier frequency division multiple access) systems.

[0003] In particular, as many communication devices require large communication capacities, enhanced mobile broadband (eMBB) communication technology is being proposed as an improvement over existing radio access technology (RAT). Furthermore, communication systems are being proposed that consider not only massive machine type communications (mmTC), which connects multiple devices and objects to provide various services anytime and anywhere, but also services and user equipment (UE) that are sensitive to reliability and latency. Various technical configurations are being proposed to achieve this.

[0004] The present disclosure may provide an apparatus and method for effectively performing quantum key exchange in a wireless communication system.

[0005] The present disclosure may provide an apparatus and a method for performing a key exchange procedure having basis independence in a wireless communication system.

[0006] The present disclosure may provide an apparatus and method for separately generating a transmit basis for transmitting an initial quantum key stream and a measurement basis for measuring a received initial quantum key stream in a wireless communication system.

[0007] The present disclosure may provide an apparatus and method for sharing a transmitting base and a measuring base in a wireless communication system.

[0008] The present disclosure may provide an apparatus and method for performing quantum key exchange based on whether there is a match between a transmitting base of a first device and a measuring base of a second device in a wireless communication system.

[0009] The present disclosure may provide an apparatus and method for preventing the loss of the rate of shifted keys generated by quantum key exchange in a wireless communication system.

[0010] The present disclosure may provide an apparatus and method for performing a quantum bit error rate (QBER) check without random qubit selection in a wireless communication system.

[0011] The present disclosure may provide an apparatus and method for selecting test qubits for QBER inspection based on a transmitting basis and a measuring basis in a wireless communication system.

[0012] The present disclosure may provide an apparatus and method for selecting inspection qubits for QBER inspection based on matching information between bases in a wireless communication system.

[0013] The technical objectives to be achieved in this disclosure are not limited to those mentioned above, and other unmentioned technical problems may be considered by those skilled in the art to which the technical configuration of this disclosure applies, based on the embodiments of this disclosure described below.

[0014] As an example of the present disclosure, the method comprises the steps of: performing a connection procedure with a second device by means of a first device; establishing a connection with the second device; transmitting capability information to the second device; establishing at least one quantum channel with the second device; and performing a quantum key exchange using the at least one quantum channel, wherein the quantum key exchange may be performed using different transmit basis and measurement basis.

[0015] As an example of the present disclosure, the method comprises the steps of establishing at least one quantum channel with a second device by means of a first device, and performing a quantum key exchange using said at least one quantum channel, wherein the quantum key exchange may be performed using different transmit basis and measurement basis.

[0016] As an example of the present disclosure, a first device comprises a transceiver and a processor coupled to the transceiver, wherein the processor is configured to perform a connection procedure with a second device, establish a connection with the second device, transmit capability information to the second device, establish at least one quantum channel with the second device, and perform a quantum key exchange using the at least one quantum channel, wherein the quantum key exchange may be performed using different transmit basis and measurement basis.

[0017] As an example of the present disclosure, a second device comprises a transceiver and a processor coupled to the transceiver, wherein the processor is configured to establish at least one quantum channel with the second device by the first device and to perform a quantum key exchange using the at least one quantum channel, and wherein the quantum key exchange may be performed using different transmit basis and measurement basis.

[0018] As an example of the present disclosure, the first device comprises at least one processor, and at least one memory connected to the at least one processor and storing instructions that cause a terminal to perform operations as executed by the at least one processor, wherein the operations include performing a connection procedure with a second device, establishing a connection with the second device, transmitting capability information to the second device, establishing at least one quantum channel with the second device, and performing a quantum key exchange using the at least one quantum channel, wherein the quantum key exchange may be performed using different transmit basis and measurement basis.

[0019] As an example of the present disclosure, in a non-transitory computer-readable medium storing at least one program instruction, the at least one program instruction causes a first device to perform operations as executed by at least one processor, said operations include performing a connection procedure with a second device, establishing a connection with the second device, transmitting capability information to the second device, establishing at least one quantum channel with the second device, and performing a quantum key exchange using the at least one quantum channel, said quantum key exchange may be performed using different transmit basis and measurement basis.

[0020] The embodiments of the present disclosure described above are merely some of the preferred embodiments of the present disclosure, and various embodiments reflecting the technical features of the present disclosure can be derived and understood by those skilled in the art based on the detailed description of the present disclosure set forth below.

[0021] The following effects may be achieved by embodiments based on the present disclosure.

[0022] According to the present disclosure, it is possible to effectively share a quantum symmetric key without loss of key rate.

[0023] The effects obtainable from the embodiments of the present disclosure are not limited to those mentioned above, and other unmentioned effects can be clearly derived and understood by a person skilled in the art to which the technical configuration of the present disclosure applies from the description of the embodiments of the present disclosure below. That is, unintended effects resulting from implementing the configuration described in the present disclosure can also be derived by a person skilled in the art from the embodiments of the present disclosure.

[0024] The drawings attached below are intended to aid in understanding the present disclosure and may provide embodiments of the present disclosure together with the detailed description. However, the technical features of the present disclosure are not limited to specific drawings, and features disclosed in each drawing may be combined with one another to form new embodiments. Reference numerals in each drawing may denote structural elements.

[0025] FIG. 1 illustrates an example of a communication system applicable to the present disclosure.

[0026] FIG. 2 illustrates an example of a wireless device applicable to the present disclosure.

[0027] FIG. 3 illustrates a method for processing a transmission signal applicable to the present disclosure.

[0028] FIG. 4 illustrates a communication procedure between a terminal and a base station applicable to the present disclosure.

[0029] FIG. 5 illustrates an example of a communication structure that can be provided in a 6G (6th generation) system applicable to the present disclosure.

[0030] FIG. 6 illustrates an electromagnetic spectrum applicable to the present disclosure.

[0031] FIG. 7 illustrates a transmitter structure applicable to the present disclosure.

[0032] FIG. 8 illustrates an example of a functional framework for the application of artificial intelligence technology applicable to the present disclosure.

[0033] FIG. 9 illustrates an example of a procedure for utilizing an artificial intelligence model applicable to the present disclosure.

[0034] FIG. 10 illustrates a communication procedure based on artificial intelligence (AI) technology applicable to the present disclosure.

[0035] Figure 11 illustrates an example of a general scenario for a quantum channel.

[0036] Figure 12 illustrates examples of quantum communication for classical bits and quantum communication for quantum bits.

[0037] FIG. 13 illustrates examples of basic properties of quantum information that can be used in information communication.

[0038] Figure 14 illustrates an example of a quantum key distribution procedure according to the BB84 protocol.

[0039] FIG. 15 illustrates an example of a protocol of DL04 QSDC according to one embodiment of the present disclosure.

[0040] FIG. 16 illustrates an example of a procedure for transmitting quantum information in a two-stage quantum secure direct communication according to one embodiment of the present disclosure.

[0041] Figure 17 illustrates an example of a Diffie-Hellman (DH) key exchange procedure.

[0042] Figures 18a and 18b illustrate the entire protocol flow of a two-way quantum key exchange (QKE) method based on symmetric procedure characteristics.

[0043] Figures 19a and 19b illustrate the overall protocol flow of different bidirectional QKE methods based on symmetric procedure characteristics.

[0044] FIGS. 20a and FIGS. 20b illustrate examples of procedures for exchanging keys based on a bidirectional QKE method having underlying independence according to one embodiment of the present disclosure.

[0045] FIG. 21 illustrates an example of a procedure in which a first device according to one embodiment of the present disclosure performs a quantum key exchange.

[0046] FIG. 22 illustrates an example of a procedure in which a second device according to one embodiment of the present disclosure performs a quantum key exchange.

[0047] FIG. 23 illustrates an example of a wireless device applicable to the present disclosure.

[0048] FIG. 24 illustrates an example of a portable device applicable to the present disclosure.

[0049] FIG. 25 illustrates an example of a vehicle or autonomous vehicle applicable to the present disclosure.

[0050] FIG. 26 illustrates an example of a vehicle applicable to the present disclosure.

[0051] FIG. 27 illustrates an example of an extended reality (XR) device applicable to the present disclosure.

[0052] FIG. 28 illustrates an example of a robot applicable to the present disclosure.

[0053] FIG. 29 illustrates an example of an AI device applicable to the present disclosure.

[0054] FIG. 30 illustrates an example of a quantum communication device applicable to the present disclosure.

[0055] The following embodiments are combinations of the components and features of the present disclosure in a predetermined form. Each component or feature may be considered optional unless otherwise explicitly stated. Each component or feature may be implemented in a form not combined with other components or features. Additionally, some components and / or features may be combined to form embodiments of the present disclosure. The order of operations described in the embodiments of the present disclosure may be changed. Some components or features of any embodiment may be included in other embodiments, or may be replaced with corresponding components or features of other embodiments.

[0056] In the description of the drawings, procedures or steps that could obscure the gist of the present disclosure have not been described, nor have procedures or steps that are understandable to those skilled in the art been described.

[0057] Throughout the specification, when a part is described as "comprising" or "including" a component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components. Furthermore, terms such as "...part," "...unit," and "module" as used in the specification refer to a unit that performs at least one function or operation, and this may be implemented in hardware, software, or a combination of hardware and software. Additionally, "one (a or an)," "one," "the," and similar related terms may be used in the context describing the present disclosure (particularly in the context of the following claims) in both singular and plural forms, unless otherwise indicated in the specification or clearly contradicted by the context.

[0058] In this specification, the embodiments of the present disclosure are described with a focus on the data transmission and reception relationship between a base station and a mobile station. Here, the base station refers to a terminal node of a network that communicates directly with a mobile station. Specific operations described in this document as being performed by a base station may, in some cases, be performed by an upper node of the base station.

[0059] That is, in a network consisting of multiple network nodes including a base station, various operations performed for communication with a mobile station may be performed by the base station or other network nodes other than the base station. In this case, 'base station' may be replaced by terms such as fixed station, Node B, eNB (eNode B), gNB (gNode B), ng-eNB, advanced base station (ABS), or access point.

[0060] Additionally, in embodiments of the present disclosure, the term terminal may be replaced with terms such as user equipment (UE), mobile station (MS), subscriber station (SS), mobile subscriber station (MSS), mobile terminal, or advanced mobile station (AMS).

[0061] Furthermore, the transmitting end refers to a fixed and / or mobile node that provides data or voice services, and the receiving end refers to a fixed and / or mobile node that receives data or voice services. Therefore, in the case of the uplink, a mobile station can be the transmitting end and a base station can be the receiving end. Similarly, in the case of the downlink, a mobile station can be the receiving end and a base station can be the transmitting end.

[0062] Embodiments of the present disclosure may be supported by standard documents disclosed in at least one of the wireless access systems, such as IEEE 802.xx systems, 3GPP (3rd Generation Partnership Project) systems, 3GPP LTE (Long Term Evolution) systems, 3GPP 5G (5th generation) NR (New Radio) systems and 3GPP2 systems, and in particular, embodiments of the present disclosure may be supported by 3GPP TS (technical specification) 38.211, 3GPP TS 38.212, 3GPP TS 38.213, 3GPP TS 38.321 and 3GPP TS 38.331 documents.

[0063] In addition, the embodiments of the present disclosure may be applied to other wireless access systems and are not limited to the systems described above. For example, they may be applicable to systems applied after the 3GPP 5G NR system and are not limited to specific systems.

[0064] That is, obvious steps or parts not described in the embodiments of the present disclosure may be described by referring to the aforementioned documents. Additionally, all terms disclosed in this document may be explained by the aforementioned standard documents.

[0065] Hereinafter, preferred embodiments according to the present disclosure will be described in detail with reference to the accompanying drawings. The detailed description disclosed below, together with the accompanying drawings, is intended to describe exemplary embodiments of the present disclosure and is not intended to represent the only embodiment in which the technical configuration of the present disclosure can be implemented.

[0066] Additionally, specific terms used in the embodiments of the present disclosure are provided to aid in understanding the present disclosure, and the use of such specific terms may be modified in other forms without departing from the technical spirit of the present disclosure.

[0067] The following technology can be applied to various wireless access systems such as CDMA (code division multiple access), FDMA (frequency division multiple access), TDMA (time division multiple access), OFDMA (orthogonal frequency division multiple access), and SC-FDMA (single carrier frequency division multiple access).

[0068]

[0069] For the sake of clarity, the following description is based on 3GPP communication systems (e.g., LTE, NR, etc.), but the technical scope of this disclosure is not limited thereto. LTE may refer to technology from 3GPP TS 36.xxx Release 8 onwards. Specifically, LTE technology from 3GPP TS 36.xxx Release 10 onwards is referred to as LTE-A, and LTE technology from 3GPP TS 36.xxx Release 13 onwards may be referred to as LTE-A pro. 3GPP NR may refer to technology from TS 38.xxx Release 15 onwards. 3GPP 6G may refer to technology from TS Release 17 and / or Release 18 onwards. "xxx" indicates a specific standard document number. LTE / NR / 6G may be collectively referred to as 3GPP systems.

[0070] Regarding the background technology, terms, abbreviations, etc. used in this disclosure, reference may be made to standard documents published prior to this disclosure. For example, reference may be made to standard documents 36.xxx and 38.xxx.

[0071]

[0072] Communication systems applicable to the present disclosure

[0073] Although not limited thereto, the various descriptions, functions, procedures, proposals, methods, and / or flowcharts of the disclosure disclosed in this document may be applied to various fields requiring wireless communication / connection (e.g., 5G) between devices.

[0074] Examples are provided in more detail below with reference to the drawings. In the following drawings and descriptions, the same reference numerals may represent the same or corresponding hardware blocks, software blocks, or function blocks unless otherwise described.

[0075] FIG. 1 illustrates an example of a communication system to which the present disclosure applies.

[0076] Referring to FIG. 1, the communication system (100) to which the present disclosure applies includes a wireless device, a base station, and a network. Here, the wireless device refers to a device that performs communication using wireless access technology (e.g., LTE, LTE-A, LTE-A pro, NR, 5G, 5G-A, 6G) and may be referred to as a communication / wireless / 5G device. Although not limited thereto, the wireless device may include a robot (100a), a vehicle (100b-1, 100b-2), an XR (extended reality) device (100c), a hand-held device (100d), a home appliance (100e), an IoT (Internet of Thing) device (100f), and an AI (artificial intelligence) device / server (100g). For example, the vehicle may include a vehicle equipped with wireless communication capabilities, an autonomous vehicle, a vehicle capable of performing inter-vehicle communication, etc. Here, the vehicle (100b-1, 100b-2) may include an unmanned aerial vehicle (UAV) (e.g., a drone). The XR device (100c) includes an augmented reality (AR) / virtual reality (VR) / mixed reality (MR) device and may be implemented in the form of a head-mounted device (HMD), a head-up display (HUD) equipped in a vehicle, a television, a smartphone, a computer, a wearable device, a home appliance, digital signage, a vehicle, a robot, etc. The portable device (100d) may include a smartphone, a smartpad, a wearable device (e.g., a smartwatch, smart glasses), a computer (e.g., a laptop, etc.). The home appliance (100e) may include a TV, a refrigerator, a washing machine, etc. The IoT device (100f) may include a sensor, a smart meter, etc.For example, the base station (120) and network (130) may also be implemented as wireless devices, and a specific wireless device (120a) may act as a base station / network node to other wireless devices.

[0077] Wireless devices (100a to 100f) can be connected to a network (130) through a base station (120). AI technology may be applied to the wireless devices (100a to 100f), and the wireless devices (100a to 100f) can be connected to an AI server (100g) through the network (130). The network (130) can be configured using a 3G network, a 4G (e.g., LTE) network, a 5G (e.g., NR) network, or a 6G network. The wireless devices (100a to 100f) may communicate with each other through the base station (120) / network (130), but may also communicate directly (e.g., sidelink communication) without going through the base station (120) / network (130). For example, vehicles (100b-1, 100b-2) can communicate directly (e.g., V2V (vehicle to vehicle) / V2X (vehicle to everything) communication). Also, an IoT device (100f) (e.g., a sensor) can communicate directly with another IoT device (e.g., a sensor) or other wireless devices (100a to 100f).

[0078] Wireless communication / connection (150a, 150b, 150c) can be established between wireless devices (100a to 100f) / base station (120) and between base station (120) / base station (120). Here, wireless communication / connection can be established through various wireless access technologies such as uplink / downlink communication (150a), sidelink communication (150b) (or D2D communication), and communication between base stations (150c) (e.g., relay, IAB (integrated access backhaul)). Through wireless communication / connection (150a, 150b, 150c), wireless devices and base stations / wireless devices, and base stations and base stations can transmit / receive wireless signals to / from each other. For example, wireless communication / connection (150a, 150b, 150c) can transmit / receive signals through various physical channels. To this end, based on the various proposals of the present disclosure, at least some of the following may be performed: a process for setting various configuration information for transmitting / receiving wireless signals, a process for various signal processing (e.g., channel encoding / decoding, modulation / demodulation, resource mapping / demapping, etc.), a resource allocation process, etc.

[0079]

[0080] Devices applicable to the present disclosure

[0081] FIG. 2 illustrates an example of a wireless device that can be applied to the present disclosure.

[0082] Referring to FIG. 2, the wireless device (200) can transmit and receive wireless signals through various wireless access technologies (e.g., LTE, LTE-A, LTE-A pro, NR, 5G, 5G-A, 6G). The wireless device (200) includes at least one processor (202) and at least one memory (204), and may additionally include at least one transceiver (206) and / or at least one antenna (208).

[0083] The processor (202) controls the memory (204) and / or the transceiver (206) and may be configured to implement the descriptions, functions, procedures, proposals, methods, and / or sequences of operation disclosed in this document. For example, the processor (202) may process information within the memory (204) to generate a first information / signal and then transmit a wireless signal containing the first information / signal through the transceiver (206). Additionally, the processor (202) may receive a wireless signal containing a second information / signal through the transceiver (206) and then store information obtained from the signal processing of the second information / signal in the memory (204). The memory (204) may be connected to the processor (202) and may store various information related to the operation of the processor (202). For example, memory (204) may store software code containing instructions for performing some or all of the processes controlled by the processor (202) or for performing the descriptions, functions, procedures, proposals, methods, and / or sequences of operations disclosed in this document. Here, the processor (202) and memory (204) may be part of a communication modem / circuit / chip designed to implement wireless communication technology. A transceiver (206) may be connected to the processor (202) and may transmit and / or receive wireless signals through at least one antenna (208). The transceiver (206) may include a transmitter and / or receiver. The transceiver (206) may be interchangeable with a radio frequency (RF) unit. In this disclosure, a wireless device may mean a communication modem / circuit / chip.

[0084] Hereinafter, hardware elements of the wireless device (200) will be described in more detail. Although not limited thereto, at least one protocol layer may be implemented by at least one processor (202). For example, at least one processor (202) may implement at least one layer (e.g., functional layers such as PHY (physical), MAC (media access control), RLC (radio link control), PDCP (packet data convergence protocol), RRC (radio resource control), and SDAP (service data adaptation protocol). At least one processor (202) may generate at least one PDU (Protocol Data Unit) and / or at least one SDU (service data unit) according to the descriptions, functions, procedures, proposals, methods and / or operation sequences disclosed in this document. At least one processor (202) may generate messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods and / or operation sequences disclosed in this document. At least one processor (202) may generate a signal (e.g., baseband signal) including a PDU, SDU, message, control information, data, or information according to the functions, procedures, proposals, and / or methods disclosed in this document and provide it to at least one transceiver (206). At least one processor (202) may receive a signal (e.g., baseband signal) from at least one transceiver (206) and may obtain a PDU, SDU, message, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and / or operation sequences disclosed in this document.

[0085] At least one processor (202) may be referred to as a controller, microcontroller, microprocessor, or microcomputer. At least one processor (202) may be implemented by hardware, firmware, software, or a combination thereof. For example, at least one application-specific integrated circuit (ASIC), at least one digital signal processor (DSP), at least one digital signal processing device (DSPD), at least one programmable logic device (PLD), or at least one field programmable gate array (FPGA) may be included in at least one processor (202). The descriptions, functions, procedures, proposals, methods, and / or operation sequences disclosed in this document may be implemented using firmware or software, and the firmware or software may be implemented to include modules, procedures, functions, etc. Firmware or software configured to perform the descriptions, functions, procedures, proposals, methods, and / or operation sequences disclosed in this document may be included in at least one processor (202) or stored in at least one memory (204) and driven by at least one processor (202). The descriptions, functions, procedures, proposals, methods, and / or flowcharts disclosed in this document may be implemented using firmware or software in the form of code, instructions, and / or sets of instructions.

[0086] At least one memory (204) may be connected to at least one processor (202) and may store various forms of data, signals, messages, information, programs, codes, instructions, and / or commands. At least one memory (204) may be composed of ROM (read-only memory), RAM (random access memory), EPROM (erasable programmable read-only memory), flash memory, hard drive, registers, cache memory, computer read storage media, and / or combinations thereof. At least one memory (204) may be located inside and / or outside of at least one processor (202). Additionally, at least one memory (204) may be connected to at least one processor (202) via various technologies, such as wired or wireless connections.

[0087] At least one transceiver (206) may transmit user data, control information, wireless signals / channels, etc., as mentioned in the methods and / or operation flowcharts, etc. of this document to at least one other device. At least one transceiver (206) may receive user data, control information, wireless signals / channels, etc., as mentioned in the descriptions, functions, procedures, proposals, methods and / or operation flowcharts, etc. disclosed in this document from at least one other device. For example, at least one transceiver (206) may be connected to at least one processor (202) and may transmit and receive wireless signals. For example, at least one processor (202) may control at least one transceiver (206) to transmit user data, control information, or wireless signals to at least one other device. Additionally, at least one processor (202) may control at least one transceiver (206) to receive user data, control information, or wireless signals from at least one other device. Additionally, at least one transceiver (206) may be connected to at least one antenna (208), and at least one transceiver (206) may be configured to transmit and receive user data, control information, wireless signals / channels, etc., as described in the descriptions, functions, procedures, proposals, methods, and / or operation sequence diagrams disclosed in this document through at least one antenna (208). In this document, at least one antenna may be a plurality of physical antennas or a plurality of logical antennas (e.g., antenna ports). At least one transceiver (206) may convert the received wireless signals / channels, etc., from RF band signals to baseband signals in order to process the received user data, control information, wireless signals / channels, etc., using at least one processor (202). At least one transceiver (206) may convert the processed user data, control information, wireless signals / channels, etc., from baseband signals to RF band signals using at least one processor (202).To this end, at least one transceiver (206) may include an (analog) oscillator and / or filter.

[0088] The components of the wireless device described with reference to FIG. 2 may be referred to by other terms in terms of their function. For example, the processor (202) may be referred to as the control unit, the transceiver (206) as the communication unit, and the memory (204) as the storage unit. In some cases, the communication unit may be used to mean at least a part of the processor (202) and the transceiver (206).

[0089] The structure of the wireless device described with reference to FIG. 2 can be understood as the structure of at least part of various devices. For example, the structure of the wireless device exemplified in FIG. 2 may be at least part of the various devices described with reference to FIG. 1 (e.g., robot (100a), vehicle (100b-1, 100b-2), XR device (100c), portable device (100d), home appliance (100e), IoT device (100f), AI device / server (100g)). Furthermore, according to various embodiments, the device may include other components in addition to the components exemplified in FIG. 2.

[0090] For example, the device may be a portable device such as a smartphone, smartpad, wearable device (e.g., smart watch, smart glasses), or portable computer (e.g., laptop, etc.). In this case, the device may further include at least one of a power supply unit that supplies power and includes a wired / wireless charging circuit, a battery, etc., an interface unit that includes at least one port for connection with another device (e.g., audio input / output port, video input / output port), and an input / output unit for inputting and outputting video information / signals, audio information / signals, data, and / or information input by a user.

[0091] For example, the device may be a mobile device such as a mobile robot, vehicle, train, manned / unmanned aerial vehicle (AV), or ship. In this case, the device may further include at least one of a drive unit comprising at least one of an engine, motor, power train, wheel, brake, and steering device of the device; a power supply unit that supplies power and includes a wired / wireless charging circuit, battery, etc.; a sensor unit that senses state information, environmental information, and user information of the device or its surroundings; an autonomous driving unit that performs functions such as path maintenance, speed control, and destination setting; and a position measurement unit that acquires position information of the moving body through a GPS (global positioning system) and various sensors.

[0092] For example, the device may be an XR device such as an HMD, a HUD (head-up display) equipped in a vehicle, a television, a smartphone, a computer, a wearable device, a home appliance, digital signage, a vehicle, a robot, etc. In this case, the device may further include at least one of a power supply unit that supplies power and includes a wired / wireless charging circuit, a battery, etc., an input / output unit that acquires control information, data, etc. from the outside and outputs a generated XR object, and a sensor unit that senses state information, environment information, and user information of the device or the surroundings of the device.

[0093] For example, the device may be a robot that can be classified into industrial, medical, household, military, etc., depending on the purpose or field of use. In this case, the device may further include at least one of a sensor unit that senses state information, environmental information, and user information of the device or its surroundings, and a drive unit that performs various physical actions, such as moving robot joints.

[0094] For example, the device may be an AI device such as a TV, projector, smartphone, PC, laptop, digital broadcasting terminal, tablet PC, wearable device, set-top box (STB), radio, washing machine, refrigerator, digital signage, robot, vehicle, etc. In this case, the device may further include at least one of an input unit that acquires various types of data from the outside, an output unit that generates output related to sight, hearing, or touch, a sensor unit that senses state information, environmental information, and user information of the device or its surroundings, and a training unit that learns a model composed of an artificial neural network using training data.

[0095] The structure of the wireless device illustrated in FIG. 2 can be understood as part of a RAN node (e.g., base station, DU, RU, RRH, etc.). That is, the device illustrated in FIG. 2 may be a RAN node. In this case, the device may further include a wired transceiver for front haul and / or back haul communication. However, if the front haul and / or back haul communication is based on wireless communication, at least one transceiver (206) illustrated in FIG. 2 is used for front haul and / or back haul communication, and the wired transceiver may not be included.

[0096]

[0097] FIG. 3 illustrates a method for processing a transmission signal applicable to the present disclosure. For example, the transmission signal may be processed by a signal processing circuit. In this case, the signal processing circuit (300) may include scramblers (310), modulators (320), a layer mapper (330), a precoder (340), resource mappers (350), and signal generators (360). In this case, for example, the operation / function of FIG. 3 may be performed in the processor (202) and / or transceiver (206) of FIG. 2. Also, for example, the hardware elements of FIG. 3 may be implemented in the processor (202) and / or transceiver (206) of FIG. 2. For example, blocks 310 to 360 may be implemented in the processor (202) of FIG. 2. Additionally, blocks 310 to 350 may be implemented in the processor (202) of FIG. 2, and block 360 may be implemented in the transceiver (206) of FIG. 2, and are not limited to the embodiments described above.

[0098] A codeword can be converted into a wireless signal through the signal processing circuit (300) of FIG. 3. Here, the codeword is an encoded bit sequence of an information block. The information block may include a transmission block (e.g., UL-SCH transmission block, DL-SCH transmission block). Here, the information block may include AI-related data (e.g., training data, AI model data, input data, output data, etc.), and the codeword may be an encoded bit sequence corresponding to the AI-related data. The wireless signal may be transmitted through various physical channels (e.g., PUSCH, PDSCH). Specifically, the codeword may be converted into a scrambled bit sequence by scramblers (310). The scrambled sequence used for scrambling is generated based on an initialization value, which may include ID information of the wireless device, etc. The scrambled bit sequence may be modulated into a modulation symbol sequence by modulators (320). Modulation methods may include pi / 2-BPSK (pi / 2-binary phase shift keying), m-PSK (m-phase shift keying), m-QAM (m-quadrature amplitude modulation), etc.

[0099] A complex modulation symbol sequence can be mapped to at least one transmission layer by a layer mapper (330). Here, a transmission layer is a logical resource unit for mapping signals or data transmitted through spatial resources to antenna ports, and one transmission layer can correspond to one stream or one antenna port. Each complex modulation symbol included in the complex modulation symbol sequence is mapped to at least one transmission layer, thereby determining which antenna port it will be transmitted through. The modulation symbols of each transmission layer can be mapped to the corresponding antenna port(s) by a precoder (340). The output z of the precoder (340) can be obtained by multiplying the output y of the layer mapper (330) by an N-XM precoding matrix W, where N is the number of antenna ports and M is the number of transmission layers. Here, the precoder (340) can perform precoding after performing transform precoding (e.g., a discrete Fourier transform (DFT)) on the complex modulation symbols. Additionally, the precoder (340) can perform precoding without performing transform precoding.

[0100] Resource mappers (350) can map the modulation symbols of each antenna port to time-frequency resources. The time-frequency resources may include multiple symbols (e.g., CP-OFDMA symbols, DFT-s-OFDMA symbols) in the time domain and multiple subcarriers in the frequency domain. Signal generators (360) generate radio signals from the mapped modulation symbols, and the generated radio signals can be transmitted to other devices through each antenna. To this end, each of the signal generators (360) may include an inverse fast Fourier transform (IFFT) module, a cyclic prefix (CP) inserter, a digital-to-analog converter (DAC), a frequency uplink converter, etc.

[0101] The signal processing process for a received signal in a wireless device can be configured as the inverse of the signal processing process (310 to 360) of FIG. 3. For example, a wireless device (e.g., 200 in FIG. 2) can receive a wireless signal from the outside through an antenna port / transceiver. The received wireless signal can be converted into a baseband signal through a signal restorer. To this end, the signal restorer may include a frequency downlink converter, an analog-to-digital converter (ADC), a CP remover, and a fast Fourier transform (FFT) module. Subsequently, the baseband signal can be restored into a codeword through a resource de-mapper process, a postcoding process, a demodulation process, and a de-scrambling process. The codeword can be restored into the original information block through decoding. Accordingly, a signal processing circuit (not shown) for a received signal may include a signal restorer, a resource de-mapper, a postcoder, a demodulator, a de-scrambler, and a decoder.

[0102] The signal processing circuit (300) described with reference to FIG. 3 is illustrated as including a plurality of scramblers (310), modulators (320), a plurality of resource mappers (350), and a plurality of signal generators (360). However, at least one of the scramblers, modulators, resource mappers, and signal generators may be implemented as a single integrated structure. That is, the number of at least one of the scramblers, modulators, resource mappers, and signal generators may be less than the number of layers. Furthermore, at least one of the components illustrated in FIG. 3 may be omitted.

[0103]

[0104] FIG. 4 illustrates a communication procedure between a terminal and a base station applicable to the present disclosure. FIG. 4 illustrates the operation of a terminal (410) and a base station (420) transmitting and / or receiving data, and the operation performed prior to this.

[0105] Referring to FIG. 4, in step 401, the terminal (410) and the base station (420) perform synchronization. For example, the terminal (410) performs an initial cell search operation. Specifically, the terminal (410) can detect at least one synchronization signal transmitted from the base station (420) according to a predefined rule. Here, the synchronization signal may include a plurality of synchronization signals (e.g., primary synchronization signal, secondary synchronization signal) classified according to structure or use. Through this, the terminal (410) can identify the boundaries of the frame, subframe, slot, and / or symbol of the base station (420) and obtain information about the base station (420) (e.g., cell identifier).

[0106] In step 403, the terminal (410) obtains system information transmitted from the base station (420). The system information is information related to the attributes, characteristics, and / or capabilities of the base station (420) required to connect to the base station (420) and use the service, and can be classified according to content (e.g., whether it is essential for connection), transmission structure (e.g., channel used, whether it is provided on-demand), etc., and can be classified, for example, into a master information block (MIB) and a system information block (SIB). If necessary, the terminal (410) may transmit a signal requesting the system information prior to receiving the system information. The system information may include information related to AI functions. For example, the system information is information required for operations performed based on AI, and may include at least one of information related to an AI model, information related to training, and information related to inference / prediction. However, the request and provision of the system information may be performed after the random access procedure described later.

[0107] In step 405, the terminal (410) and the base station (420) perform a random access procedure. The terminal (410) may transmit and / or receive at least one message for the random access procedure (e.g., random access preamble, RAR (random access response) message, etc.) based on information related to the random access channel of the base station (420) obtained through system information (e.g., channel location, channel structure, structure of supported preamble, etc.). For example, the terminal (410) may transmit a preamble (e.g., MSG1) through the random access channel, receive a RAR message (e.g., MSG2), transmit a message (e.g., MSG3) containing information related to the terminal (410) (e.g., identification information) to the base station (420) using scheduling information included in the RAR message, and receive a message (e.g., MSG4) for contention resolution and / or connection establishment. As another example, MSG1 and MSG3 can be transmitted and received as a single message, or MSG2 and MSG4 can be transmitted and received as a single message.

[0108] In step 407, the terminal (410) and the base station (420) perform signaling of control information. Here, the control information may be defined in various layers, such as a layer that controls the connection (e.g., a radio resource control (RRC) layer), a layer that handles mapping between logical channels and transmission channels (e.g., a media access control (MAC) layer), and a layer that handles physical channels (e.g., a physical (PHY) layer). For example, the terminal (410) and the base station (420) may perform at least one of signaling to establish a connection, signaling to determine settings related to communication, and signaling to indicate allocated resources. Additionally, the signaling of control information may be performed to convey information related to AI functions. For example, information related to AI functions is information necessary for operations performed based on AI, and may include at least one of information related to an AI model, information related to training, and information related to inference / prediction. More specifically, the information related to the AI ​​function signaled in step 407 can be combined and / or combined with the information related to the AI ​​function signaled in step 403, and both can be defined as having a hierarchical, mutually complementary, or substitute structure.

[0109] In step 409, the terminal (410) and the base station (420) transmit and / or receive data. That is, the terminal (410) and the base station (420) can process, transmit and / or receive data based on the signaling of control information. For example, when transmitting data, the terminal (410) or the base station (420) may perform at least one of channel encoding, rate matching, scrambling, constellation mapping, layer mapping, waveform modulation, antenna mapping, and resource mapping on the information bits. Conversely, when receiving data, the terminal (410) or the base station (420) may perform at least one of signal extraction from resources, antenna-specific waveform demodulation, signal placement considering layer mapping, constellation demapping, descrambling, and channel decoding. Here, the transmitted data is AI-related data, and may include, for example, data for AI-based operations or data generated by AI-based operations.

[0110] Steps 401 through 409 described with reference to FIG. 4 must not necessarily be performed in the order exemplified in FIG. 4, and the order of at least some of the steps may vary. Additionally, at least some of steps 401 through 409 may be combined into a single step or omitted. That is, the steps exemplified in FIG. 4 may be performed in various modified forms.

[0111]

[0112] 6G communication systems and core implementation technologies of 6G systems

[0113] 5G systems define various operating bands within FR1 (frequency range 1), which includes 410 MHz to 7125 MHz, and FR2 (frequency range 2), which includes 24,250 MHz to 71,000 MHz. Various frequencies are being discussed as operating bands for subsequent 6G systems, and the use of frequencies higher than those of 5G systems is also being considered for wider bandwidth and higher transmission speeds. As one example, the use of the THz (Terahertz) frequency band, which includes approximately 100 GHz to 10 THz, is being discussed. The THz frequency band is a band that possesses both the penetrability of radio waves and the directivity of optical waves, and communication using the THz frequency band is expected to play a transitional role from existing radio-based communication to optical-based communication.

[0114] 6G systems utilizing the THz frequency band as described above aim for: i) very high data rates per device, ii) a very large number of connected devices, iii) global connectivity, iv) very low latency, v) reduced energy consumption of battery-free IoT devices, vi) ultra-reliable connectivity, and vii) connected intelligence with machine learning capabilities. The vision of 6G systems can be four aspects, such as "intelligent connectivity," "deep connectivity," "holographic connectivity," and "ubiquitous connectivity," and 6G systems can be designed to satisfy requirements such as those shown in [Table 1] below.

[0115] Per device peak data rate1 TbpsE2E latency1 msMaximum spectral efficiency100 bps / HzMobility supportup to 1000 km / hrSatellite integrationFullyAIFullyAutonomous vehicleFullyXRFullyHaptic CommunicationFully

[0116] At this time, the 6G system may have key factors such as enhanced mobile broadband (eMBB), ultra-reliable low latency communications (URLC), massive machine type communications (mMTC), AI integrated communication, tactile internet, high throughput, high network capacity, high energy efficiency, low backhaul and access network congestion, and enhanced data security. FIG. 5 illustrates an example of a communication structure that can be provided by a 6G system applicable to the present disclosure. Referring to FIG. 5, the 6G system is expected to have simultaneous wireless communication connectivity 50 times higher than that of a 5G wireless communication system. URLLC, a key feature of 5G, is expected to become an even more dominant technology in 6G communication by providing end-to-end latency of less than 1ms. In this case, 6G systems will have significantly superior volumetric spectral efficiency, unlike the frequently used area-spectral efficiency. Since 6G systems can provide very long battery life and advanced battery technology for energy harvesting, mobile devices in 6G systems may not need to be charged separately. New network characteristics in 6G may be as follows.

[0117] - Satellite Integrated Network: 6G is expected to be integrated with satellites to provide a global mobile population. Integrating terrestrial, satellite, and airborne networks into a single wireless communication system is crucial for 6G.

[0118] - Connected Intelligence: Unlike previous generations of wireless communication systems, 6G is innovative and will update wireless evolution from "connected things" to "connected intelligence." AI can be applied at each stage of the communication process (or at each step of the signal processing described below).

[0119] - Seamless integration of wireless information and energy transfer: 6G wireless networks will transfer power to charge the batteries of devices such as smartphones and sensors. Therefore, wireless information and energy transfer (WIET) will be integrated.

[0120] - Ubiquitous Super 3D Connectivity: Connectivity to the network and core network functions of drones and very low Earth orbit satellites will create Super 3D connectivity in 6G ubiquitous.

[0121] Some general requirements regarding the new network characteristics of 6G mentioned above may be as follows.

[0122] - Small cell networks: The idea of ​​small cell networks was introduced to improve the quality of received signals in cellular systems as a result of increased throughput, energy efficiency, and spectrum efficiency. Consequently, small cell networks are an essential feature of communication systems for 5G and beyond 5G (5GB). Therefore, 6G communication systems also adopt the characteristics of small cell networks.

[0123] - Ultra-dense heterogeneous network: Ultra-dense heterogeneous networks will be another important characteristic of 6G communication systems. Multi-tier networks composed of heterogeneous networks improve overall QoS and reduce costs.

[0124] - High-capacity backhaul: Backhaul connections are characterized as high-capacity backhaul networks to support high-volume traffic. High-speed fiber optics and free-space optics (FSO) systems can be possible solutions to this problem.

[0125] - Radar technology integrated with mobile technology: High-precision localization (or location-based services) through communication is one of the functions of 6G wireless communication systems. Therefore, radar systems will be integrated with 6G networks.

[0126] - Softwarization and virtualization: Softwarization and virtualization are two important features that form the basis of the design process in 5GB networks to ensure flexibility, reconfigurability, and programmability. Additionally, billions of devices can be shared across a shared physical infrastructure.

[0127] To satisfy the aforementioned characteristics, technologies such as artificial intelligence (AI), THz (Terahertz) communication, optical wireless technology, FSO backhaul network, massive MIMO technology, blockchain, 3D networking, quantum communication, unmanned aerial vehicles, cell-free communication, wireless information and energy transfer (WIET), integration of sensing and communication, integration of access backhaul networks, holographic beamforming, big data analysis, and large intelligent surface (LIS) may be adopted as core implementation technologies of the 6G system.

[0128] For example, THz communication can be utilized in 6G systems. THz communication is a communication that uses a spectrum in the frequency band between 0.3 THz and 3 THz with a corresponding wavelength in the range of 0.1 mm to 1 mm as shown in Fig. 6. Referring to Fig. 6, the frequency band of the THz wave is located in the intermediate region between the infrared band and the millimeter wave band; accordingly, the THz wave can be understood as a radio wave with the shortest wavelength and, at the same time, a light wave with the longest wavelength. As a result, the THz wave shares some characteristics of infrared and microwave waves, and specifically, can simultaneously possess the penetrability of electromagnetic waves and the directivity of light waves.

[0129]

[0130] FIG. 7 illustrates a transmitter structure applicable to the present disclosure.

[0131] Referring to Fig. 7, in order to modulate data onto an optical signal, the optical source of a laser can be passed through an optical wave guide to change the phase of the signal. At this time, data is loaded by changing electrical characteristics through a microwave contact, etc. Therefore, the optical modulator output is formed as a modulated waveform.

[0132] Data may be provided by a data signal generator. Here, the data may include various user data, configuration information, control information, etc. transmitted through a channel. Furthermore, the data may include data related to AI-based operations, for example, information for configuring an AI model, input / output data for tasks of an AI model, etc. To this end, components related to AI functions (e.g., an AI processing unit) may be included in the data signal generator or may interact with the data signal generator.

[0133] An O / E converter can generate THz pulses based on optical rectification by a nonlinear crystal, O / E conversion by a photoconductive antenna, emission from a bundle of relativistic electrons, etc. THz pulses generated in such a manner can have a length ranging from femtoseconds to picoseconds. The O / E converter performs down-conversion by utilizing the non-linearity of the device.

[0134] When considering the usage of the THz spectrum, it is highly likely that multiple contiguous GHz bands will be used for fixed or mobile service applications for THz systems. According to outdoor scenario criteria, available bandwidth can be classified based on an oxygen attenuation of 10^2 dB / km in the spectrum up to 1 THz. Accordingly, a framework in which the available bandwidth is composed of multiple band chunks can be considered. As an example of the above framework, if the length of the THz pulse for a single carrier is set to 50 ps, ​​the bandwidth (BW) becomes approximately 20 GHz.

[0135] Effective down-conversion from the infrared band to the THz band depends on how the nonlinearity of the photoelectric converter (O / E converter) is utilized. In other words, to achieve down-conversion to the desired THz band, it is required to design an O / E converter with the most ideal nonlinearity for transferring to that specific band. If an O / E converter that does not match the target frequency band is used, there is a high probability of errors occurring regarding the amplitude and phase of the corresponding pulse.

[0136] In a single-carrier system, a THz transceiver system can be implemented using a single photoelectric converter. Depending on the channel environment, in a multi-carrier system, as many photoelectric converters as there are carriers may be required. This phenomenon will be particularly pronounced in multi-carrier systems utilizing multiple broadbands according to the plans related to the aforementioned spectrum applications. In this regard, a frame structure for the multi-carrier system may be considered. A signal down-frequency converted based on a photoelectric converter can be transmitted in a specific resource region (e.g., a specific frame). The frequency domain of the specific resource region may include multiple chunks. Each chunk may consist of at least one component carrier (CC).

[0137]

[0138] AI technology can be introduced in 6G systems. Efficient resource management and optimization are required to maintain connectivity between various services and devices. AI technology may include techniques capable of performing data analysis, pattern recognition, and predictive modeling using AI / ML (artificial intelligence / machine learning) models. Here, an AI / ML model can be understood as a set of parameter values ​​and / or weight values ​​related to mathematical formulas or algorithms generated through learning, designed to discover patterns in input data or perform predictions. To create such an AI / ML model, an AI / ML model training procedure is required to build the model by learning the relationship between input and output in a data-driven manner. Various learning algorithms, such as supervised learning, unsupervised learning, and reinforcement learning, can be utilized as training algorithms. Users can input specific data into a trained AI / ML model to generate output, and the procedure of obtaining output data by inputting input data into the AI / ML model can be referred to as AI / ML 'inference' or 'prediction'.

[0139] Network control parameters can be obtained as output through AI / ML inference using trained AI / ML models. Users can improve network efficiency by utilizing these output parameter values. For example, AI technology can be applied in various fields, such as wireless network resource allocation, traffic management, fault prediction, and Quality of Service (QoS) management. In particular, machine learning can efficiently allocate resources even in dynamically changing network environments based on real-time data. Therefore, AI technology can be utilized to provide hyper-connectivity and ultra-low latency.

[0140] In this case, AI / ML inference can be performed based on a combination of various devices. For example, the UE and the network can jointly perform AI / ML inference, and such an AI / ML model may be referred to as a two-sided AI / ML model or a two-sided model. In this case, the UE may perform the first part of the inference first, and the base station may perform the remaining inference, and vice versa. As another example, all inference may be performed by the UE, and such an AI / ML model may be referred to as a UE-side AI / ML model or a UE-side model.

[0141] In addition, life cycle management (LCM) for AI / ML models can be performed. Life cycle management may include model training, model deployment, model inference, model monitoring, and model updating. To this end, support may be required for data collection, model training, functionality / model identification, model delivery / transfer, model inference operations, functionality / model selection / enable / disable / fallback, functionality / model monitoring, model updating, and UE capabilities.

[0142] For example, AI / ML technology can be operated based on a functional framework such as FIG. 8. FIG. 8 illustrates an example of a functional framework for the application of AI / ML technology applicable to the present disclosure. First, a data collection function (810) generates training data (801), monitoring data (803), and / or inference data (805) containing processed input data by performing data preparation on input data collected from objects (e.g., UE, RAN node, network node, etc.). A model training function (820), having received the training data (801) from the data collection function (810), performs training on an AI / ML model using the training data (801) and provides the trained / updated model (813) to a model repository (840). The model repository (840) can store and retain the received trained / updated model (813).

[0143] A management function (830) may be used to control AI / ML model training. The management function (830) may control the operation of AI / ML models or AI / ML functions, or supervise their performance. To this end, the management function (830) may receive monitoring data (830) from the data collection function (810) and receive inference output (809) from the inference function (840). The management function (830) performs the role of managing the inference operation so that it can be performed efficiently based on the data received from the data collection function (810) and the inference function (840). That is, the management function (830) may transmit performance feedback or a retraining request (807) to the model training function (820) to improve the inference operation. Here, the performance feedback may be used to direct the learning goal or as a reward for reinforcement learning. Additionally, the management function (830) can provide management instructions (811) that instruct the inference function (840) to select AI / ML models or AI / ML-based functions to use, enable / disable them, or switch to non-AI / ML operations.

[0144] The inference function (840) generates an inference output (809) by performing inference and / or prediction using inference data (805) received by the data collection function (810). Here, the inference output (809) refers to the inference output of the AI / ML model used by the inference function (840), and the details of the inference output may vary depending on the use case. The AI / ML model used by the inference function (840) can be controlled by the management function (830). That is, the management function (830) can transmit a model transmission / delivery request signal (815) to the model repository function (850) to request the necessary AI / ML model, and the model repository function (850) can transmit the corresponding AI / ML model to the inference function (840) via a model transmission / delivery signal (817). Thus, the inference function (840) can perform inference using the AI / ML model (817) according to the received management instructions (811).

[0145] Additionally, the management function (830) can trigger or perform a specified task / action based on the inference output (809). Thus, the management function (830) can trigger a task / action on other objects (e.g., at least one UE, at least one RAN node, at least one network node, etc.) or on itself. Any one of the functions exemplified in FIG. 8 described above may be performed by two or more entities among the RAN, network node, network operator's OAM, or UE in collaboration. This may be referred to as a split AI operation.

[0146] To use an AI / ML model, not all of the functions (810 to 850) illustrated in FIG. 8 must be used, and the method of combining them is not limited to a specific method. Therefore, the functions (810 to 850) may be operated in an integrated manner, or some functions may be omitted. Furthermore, the functions (810 to 850) illustrated in FIG. 8 are not necessarily limited to being implemented as separate devices or apparatuses. For example, some or all of the functions (810 to 850) may be included in the processor (202) of FIG. 2. Additionally, the model storage function (850) may be included in the memory (204) of FIG. 2.

[0147]

[0148] FIG. 9 illustrates an example of a procedure for utilizing an AI model applicable to the present disclosure. FIG. 9 illustrates a case where a model training function (820) is included in a network node and a model inference function (840) is included in a RAN node. Referring to FIG. 9, in step 1, RAN node 1 and RAN node 2 transmit input data (e.g., training data) for training an AI model to a network node. Here, RAN node 1 and RAN node 2 may also transmit data collected from a UE (e.g., UE measurements related to RSRP, RSRQ, SINR of a serving cell and neighboring cells, UE location, velocity, etc.) to the network node. In step 2, the network node trains the AI ​​model using the received training data. In step 3, the network node distributes / updates the AI ​​model to RAN node 1 and / or RAN node 2. RAN node 1 and / or RAN node 2 may continue to perform model training based on the received AI model. In this procedure, it is assumed that the AI ​​model is deployed / updated only to RAN Node 1. In Step 4, RAN Node 1 receives input data (e.g., inference data) for AI model inference from the UE and RAN Node 2. In Step 5, RAN Node 1 generates output data (e.g., prediction or decision) by performing AI model-based inference using the received inference data. In Step 6, if applicable, RAN Node 1 may transmit model performance feedback to the network nodes. In Step 7, RAN Node 1, RAN Node 2, and the UE (or 'RAN Node 1 and UE', or 'RAN Node 1 and RAN Node 2') perform an action based on the output data. For example, in the case of a load balancing action, the UE may move from RAN Node 1 to RAN Node 2. In Step 8, RAN Node 1 and RAN Node 2 transmit feedback information to the network nodes.

[0149] Network nodes can manage AI models based on feedback information regarding the inference results of AI models. For example, network nodes can perform additional training on AI models or generate additional information about AI models (e.g., performance information, accuracy information, etc.). If additional training is performed on AI models, network nodes can distribute the updated AI models to RAN node 1.

[0150] As explained with reference to Fig. 9, model training can be performed by network nodes, and inference using the model can be performed by RAN node 1. In other words, the model training and inference functions can be distributed. Generally, model training requires a large amount of computational resources because it involves optimization using large amounts of data and complex algorithms. In contrast, inference is a process of drawing conclusions about new data using an already trained model, and therefore requires relatively fewer computational resources compared to model training. Therefore, by using the procedure of Fig. 9, model training can be performed through network nodes if the computational resources of the UE or RAN nodes are insufficient. Additionally, security regarding the AI ​​model can be ensured because the AI ​​model is not exposed to the UE.

[0151] FIG. 9 illustrates a case where the model training function (820) is included in a network node and the model inference function (840) is included in a RAN node, but the present disclosure is not limited thereto. For example, if the computational resources of the RAN node are sufficient, both the model training function (820) and the model inference function (840) may be included in RAN node 1. In this case, RAN node 1 receives training data for training an AI model from the UE and RAN node 2. RAN node 1 trains the AI ​​model using the received training data. Subsequently, RAN node 1 receives inference data for AI model inference from the UE and RAN node 2. RAN node 1 generates output data by performing AI model-based inference using the received inference data. Based on the output data, the UE, RAN node 1, and RAN node 2 can perform communication-related operations (e.g., handover, cell change). Subsequently, the UE and RAN node 2 can transmit feedback regarding the operations to RAN node 1. Therefore, RAN Node 1 can train the AI ​​model and update the AI ​​model it will use through feedback information regarding the inference results of the AI ​​model. According to the aforementioned method, since signaling with the network is not required for AI model training and inference, the network load or the latency to train the AI ​​model or receive inference results can be reduced. Additionally, since the UE performs inference using the AI ​​model, the UE's personal information is not transmitted to network nodes, etc. Consequently, security regarding personal information can be enhanced.

[0152] As another example, the model training function (820) may be included in the RAN node, and the model inference function (840) may be included in the UE. The RAN node receives training data for training an AI model from the UE and trains the AI ​​model using the received training data. The RAN node distributes the trained AI model to the UE. The UE can generate output data by performing inference based on the received AI model. At this time, the data for inference can be received from the RAN node or data acquired by the UE itself can be used. The UE and the RAN node can perform communication-related operations based on the output data generated by inference. Subsequently, the UE can send feedback regarding the operation to the RAN node. Thus, through feedback information regarding the inference results of the AI ​​model, the RAN node can train the AI ​​model and distribute the updated AI model to the UE. According to the method described above, the load on the RAN node can be reduced by having the model training function (820) in the RAN node and the model inference function (840) in the UE perform inference. In addition, if the UE performs inference using data acquired independently, even if the UE loses connection to the RAN node after receiving the AI ​​model, the UE can continue to perform inference using the received AI model and operate based on the inference results.

[0153] According to the aforementioned framework and procedure, an AI model can be trained and utilized in a wireless communication system. The model training function (820) and the model inference function (840) can be combined in various ways and are not necessarily limited to the case of FIG. 9. In the aforementioned framework and procedure, various data such as input data, training data, and inference data are introduced, and the specific details of the aforementioned data may vary depending on the task in which the AI ​​model is utilized. For example, information used in the various embodiments of the present disclosure described below may be included in the aforementioned data.

[0154]

[0155] FIG. 10 illustrates an AI technology-based communication procedure applicable to the present disclosure. The detailed procedure illustrated in FIG. 10 may be combined with various embodiments of the present disclosure described below. For example, data generated according to various embodiments of the present disclosure may be used for operations (e.g., setup, training, inference, and / or data transmission / reception) in at least one of the detailed procedure illustrated in FIG. 10. As another example, the result of the inference illustrated in FIG. 10 may be used to transmit and / or receive data according to various embodiments of the present disclosure.

[0156] Referring to FIG. 10, in step S1001, at least one of the UE (1010), RAN node (1020), and network node (1030) performs an initial connection procedure. For example, in this step, at least one of an initial cell search operation, a system information acquisition operation, a random access operation, and a registration operation may be performed. In step S1003, at least one of the UE (1010), RAN node (1020), and network node (1030) performs a configuration procedure. Through the configuration procedure, parameters, resources, connections, and / or entities necessary to perform subsequent procedures at layers between the UE (1010) and the RAN node (1020) and / or at least one layer between the UE (1010) and the network node (1030) may be determined and / or created. At this time, the configuration procedure may be performed based on information, status, and / or characteristics of the AI ​​model used for subsequent training and inference.

[0157] In step S1005, at least one of the UE (1010), RAN node (1020), and network node (1030) performs a model training procedure. At least one of the UE (1010), RAN node (1020), and network node (1030) may collect training data and perform training using the training data. For example, the model training procedure may be performed as described with reference to FIG. 9. If an offline trained model is used, this step may be omitted.

[0158] In step S1007, at least one of the UE (1010), RAN node (1020), and network node (1030) performs a task using a trained model. That is, the task may be performed by the result of inference and / or prediction using the trained model. For example, the task may be a procedure belonging to a communication protocol, a preliminary operation for subsequent data transmission and / or reception, related to data transmission and / or reception, or related to data processing (e.g., encoding, decoding, etc.).

[0159] In step S1009, at least one of the UE (1010), RAN node (1020), and network node (1030) transmits and / or receives data. At this time, the result of the task performed in step 1007 may be used. In some cases, the task performed in step 1007 may include the transmission and / or reception of data, in which case this step may be omitted as it is part of step 1007.

[0160]

[0161] quantum communication (QC)

[0162] Quantum communication is a next-generation communication technology that applies quantum mechanical properties to the field of information and communications to overcome the limitations of existing technologies, such as security and ultra-high-speed computing. Quantum communication can provide means to generate, transmit, process, and store information that cannot be represented in the form of 0 and 1 based on binary bits used in conventional communication technologies, or that is difficult to represent. While conventional communication technologies utilize wavelength or amplitude for information transmission between a transmitter and a receiver, quantum communication, in contrast, utilizes photons—the smallest unit of light—for this purpose. In particular, since quantum uncertainty and quantum irreversibility can be applied to photons, or the polarization or phase difference of light, quantum communication possesses the characteristic of enabling communication with guaranteed perfect security. Furthermore, quantum communication can enable ultra-high-speed communication by utilizing quantum entanglement under specific conditions.

[0163] Quantum communication is defined as a communication system capable of exchanging information by utilizing the quantum properties of quantum physics. In a QC system, using a wired or wireless communication environment, a transmitter delivers the quantum information to be transmitted to a receiver through a quantum channel. As a foundational technology for constructing the Quantum Internet, QC can be utilized to transmit quantum information between quantum nodes.

[0164] Figure 11 illustrates an example of a general scenario for a quantum channel. In Figure 11, the quantum channel can be implemented via wired connections through fiber optics or wireless connections through free space. Qubit information can be transmitted through the direct transmission of single / multiple photons formed at a transmitter or through quantum teleportation between nodes that share an entanglement resource. The quantum channel serves as a medium for transmitting qubit information in a quantum network composed of multiple quantum processors and can be configured as a single hop or multiple hop.

[0165] Figure 12 illustrates examples of quantum communication for classical bits and quantum communication for quantum bits. Referring to Figure 12, the technology group for quantum communication can be divided into QC4Cbit (quantum communication for Classical Bit) and QC4Qbit (quantum communication for Quantum Bit), which correspond to the information exchange technology group for quantum communication, and a quantum network, which corresponds to the technology group for supporting an infrastructure network to support quantum communication.

[0166] Information in quantum communication includes both bit information, the basic unit of classical information, and qubit information, the basic unit of quantum information. Here, a qubit can be referred to as a quantum bit.

[0167] Quantum communication can be classified into QC4Cbit and QC4Qbit depending on the type of information to be transmitted. QC4Cbit converts the classical bit information to be transmitted into a qubit basis or computation basis in a quantum encoder, with or without applying reliability enhancement techniques such as classical encoders. In this case, the classical bit information 0 or 1 is the qubit basis or It is converted into. The above qubit basis is logical information about the quantum state and can be formed by a physical quantum basis. For example, the transmitter and receiver use horizontal polarization and vertical polarization as quantum bases for the qubit basis. and It is possible to agree to correspond to [the]. A qubit basis generated at the transmitting end is transmitted to the receiving end through a quantum channel, and the receiver's quantum decoder decodes the qubit basis by performing a measurement using a pre-agreed quantum basis. The receiver obtains the desired information by converting the measured qubit basis back into classical bit information, with or without applying reliability enhancement techniques such as a channel decoder. If the qubit state is determined based on multiple qubit bases, the receiver can obtain information deterministically or probabilistically depending on which qubit basis is used for the measurement. Based on these characteristics, technology families such as quantum key distribution (QKD) in quantum cryptography and quantum secure direct communication (QSDC) in quantum direct communication can provide security between the transmitter and the receiver.

[0168] QC4Qbit is a qubit state generated by the transmitter's quantum processor It refers to a method of transmitting to a receiver via a quantum channel and using the received qubit state at the receiver according to the purpose. The qubit state received by the receiver in QC4Qbit When used in a quantum processor, the receiver is the qubit state without measurement It can be used depending on the purpose. In this case, the transmitted qubit state is a superposition state of qubit bases, and generally, = It can be expressed as. In this case, the qubit basis is and as, and is the probability amplitude, and It has a relationship. Information can be transmitted according to a method of transmitting qubit states generated in a quantum processor, such as by converting them into photons and transmitting them directly, or by performing quantum teleportation based on entanglement resources shared between a transmitter and a receiver in advance.

[0169] A quantum network is a medium that enables the exchange of quantum states between two physically separated quantum processors. The elements constituting a quantum network include quantum channels through which quantum states are exchanged, quantum repeaters connecting these channels, and quantum processors acting as entities for the purpose of information exchange. A quantum channel can be constructed through a physical channel that transmits target qubits based on photons and through entanglement shared by two nodes; in this case, intermediate nodes, such as quantum repeaters or trusted nodes, may be introduced to transmit quantum information between nodes that do not directly share entanglement. The group of quantum network technologies, serving as infrastructure network support technologies for supporting quantum communication, includes quantum resource allocation (QRA) technologies for forming quantum channels of a quantum network, as well as user authentication (e.g., quantum authentication) and data authentication technologies (e.g., quantum signatures) that provide security between transmitting and receiving nodes.

[0170] Here, quantum cryptography refers to a communication method in which the exchange of secret cryptographic keys is securely performed between a spatially separated transmitter and receiver, and encrypted communication is conducted between the transmitter and receiver using the exchanged secret keys. Additionally, quantum direct communication refers to a communication method in which classical message information to be transmitted is securely shared directly through a quantum channel. Furthermore, quantum teleportation refers to a communication method in which quantum information itself is shared through a quantum entanglement channel.

[0171] The present disclosure describes the characteristics of quantum information that form the basis of quantum communication, quantum cryptographic communication, quantum direct communication, quantum teleportation, and other technologies related to quantum communication.

[0172] Characteristics of quantum information

[0173] Since quantum communication is a means of transmitting quantum information, this section examines the characteristics of quantum information. The basic unit of information used in quantum information systems is referred to as a quantum bit or qubit. A quantum system is a linear system defined in Hilbert space, and a qubit can be represented using state vectors in Hilbert space.

[0174] Quantum states can include the following properties.

[0175] (1) Superposition

[0176] Unlike conventional digital information, a characteristic of quantum information is that information can be superimposed. In conventional digital systems, the bit, the minimum unit for processing information, holds a value of one of two different states: '0' or '1'. On the other hand, a qubit can have multiple different states in Hilbert space and can exist in a superposition state where these different states overlap. A qubit is an orthogonally normalized basis state vector existing in Hilbert space and It can be expressed as shown in [Mathematical Formula 1] below using [Equation 1].

[0177]

[0178] In [Mathematical Formula 1], and In each case, when the qubits associated with a and b are measured, the qubit states after the measurement are respectively and It means the probability of this happening.

[0179] As shown in [Mathematical Equation 1], the state of information in a quantum system exists probabilistically, and even if two pieces of quantum information existing in two quantum systems of the same state are measured in exactly the same way, the results may differ. In other words, since quantum information in a quantum system is composed of probabilities, the result of a measurement cannot be accurately predicted. The moment a qubit is measured, it collapses into one of its superposition states. That is, before a qubit is measured, it exists in a superposition state of 0 and 1, but the moment it is measured, the qubit's state becomes fixed in either 0 or 1. Furthermore, once a qubit is measured, its state cannot return to the state prior to the measurement.

[0180] (2) Entanglement

[0181] Another characteristic of quantum information is entanglement, a property that plays a very important role in differentiating quantum systems from classical information. Entanglement refers to a state where the results of different observations are closely related to each other. The entangled state in a quantum system acts more strongly than any correlation existing in classical mechanics. Two qubits can be represented in Hilbert space as a superposition of four fundamental quantum states. Here, the aforementioned four fundamental quantum states are { , , , It includes}. The fundamental quantum state of two qubits can be represented through tensor operations on the fundamental states of individual qubits. When the states of two qubits cannot be represented by the tensor product of a single qubit, such qubit states are called entangled states. As representative examples of entangled qubits, there are four cases referred to as EPR (Einstein-Podolsky-Rosen) states, which are as shown in [Equation 2] below.

[0182]

[0183]

[0184]

[0185]

[0186] In [Mathematical Formula 2] It can be used when transmitting classical information 00, and It can be written as, It can be used when transmitting classical information 10, and It can be written as, It can be used when transmitting classical information 01, and It can be written as, It can be used when transmitting classical information 11, and It can be denoted as such. The matching relationship between quantum states and classical information can be defined differently from what was previously described.

[0187] The above EPR state is also called the Bell state, and in each qubit, the measurement result of the qubit located ahead always affects the measurement of the qubit located behind. In addition, the above four pure states are all maximally entangled states and form the vertical basis of the 2-qubit Hilbert space.

[0188] (3) Non-cloning property

[0189] The non-copyable characteristic means that qubit information cannot be copied in a closed quantum information system. For example, assuming two memories capable of storing bit information in a conventional information system, the first memory stores arbitrary bit information 'a' having a value of either 0 or 1, and the second memory is initialized to '0'. In the case of a conventional information system, the state of the two memories can be changed from 'a0' to 'aa' through a copy operation. Conversely, assuming two memories capable of storing qubit information in a quantum information system, the first memory is It is initialized to, and the second memory can be initialized to '0'. In the case of a quantum information system, the memory state is at It cannot be copied. Due to this characteristic, it is impossible to implement copy-based iteration codes for error correction code design in quantum information systems.

[0190] (4) Continuous quantum error

[0191] In conventional information systems, information consists of '0' and '1', and errors are represented when '0' changes to '1' or '1' changes to '0'. Qubit It can be thought of as a single point existing on the surface of a Bloch sphere; when an error in a conventional information system occurs at a qubit, this is referred to as a bit-flip error. Such an error means that the value of 'a' changes to the value of 'b', which implies that when measuring a qubit, the measurement probability has changed from the initial value due to the error. Other forms of errors distinct from those in conventional information systems include class There is a phase flip error in which the phase between changes by 180 degrees. Errors can occur with arbitrary phases along the X-axis or Z-axis, and thus quantum errors can have continuous phases.

[0192] (5) Decay of quantum information by measurement

[0193] Quantum information exists probabilistically, and at the moment of measurement, it decays into the ground state and cannot be restored to its state before measurement. The quantum information after measurement by the measurement operator is probabilistic. and Depending on the, it collapses into one of the underlying states that make up the information. The collapsed information does not contain the information of 'a' or 'b' and cannot return to the state before measurement.

[0194] From the perspective of quantum error correction codes, in order to apply quantum error correction codes in a quantum information system, codewords must be generated without measuring information or without measurements that would alter the information during the process of encoding and restoring information, and information must be restored after estimating errors that occurred in the channel. Among the characteristics of quantum information described above, the three properties of quantum information that can be used for information communication can be summarized as shown in Figure 13 below. Figure 13 illustrates examples of the basic properties of quantum information that can be used for information communication.

[0195] Quantum cryptography

[0196] Quantum cryptographic communication refers to a method in which secret cryptographic keys are exchanged between spatially separated transmitters and receivers, and encrypted communication is performed between them using the exchanged secret keys. In next-generation communication technologies, the security of information may be treated as more important than the transmission speed or efficiency of information transmission. The purpose of information protection is to ensure that the original information cannot be identified even if it is exposed. To achieve this objective, encryption and decryption technologies, represented by encryption key generation and management technologies, are utilized, and quantum cryptography can be applied to said encryption and decryption. Quantum communication refers to the process of transmitting information contained in a quantum state from a transmitter to a receiver; at this time, the information contained in the quantum state may be binary digital information of 0 or 1, or information in which 0 and 1 are superimposed. In particular, in the case of quantum communication where binary information of 0 and 1 is transmitted in a quantum state, if someone intercepts the binary information transmitted from the sender to the receiver, the receiver immediately recognizes the presence of the interceptor, and based on this immediate recognition of the interceptor, the receiver can stop the communication and take appropriate measures to avoid interception. Quantum cryptography is the application of these characteristics of quantum communication to the transmission of cryptographic keys, and reflecting the characteristic that the sender and receiver share the cryptographic key generated by applying the characteristics of quantum communication to the transmission of cryptographic keys, the above method can be referred to as quantum key distribution (QKD).

[0197] The following describes the protocol for quantum cryptographic key distribution and the post-processing process for quantum key distribution.

[0198] (1) Quantum Key Distribution Protocol (QKD protocol)

[0199] Conventional cryptographic systems are based on the computational complexity of prime factorization algorithms; therefore, if an eavesdropper using a quantum computing device—which offers significantly faster processing speeds than conventional computing devices—is present, there is a risk of cryptographic keys being exposed due to eavesdropping during the key distribution process. Since quantum key distribution methods are based on the quantum uncertainty principle, the risk of cryptographic keys being intercepted by an eavesdropper can be completely eliminated. In the case of quantum information, quantum bits (qubits) are used as the unit of information, and when implementing quantum key distribution, qubits for distribution are realized using single photons. Photons have the advantage of being highly suitable for long-distance communication as they interact almost exclusively with each other.

[0200] The BB84 protocol, one of the representative quantum cryptography key distribution protocols, is constructed based on the uncertainty principle. Therefore, according to the BB84 protocol, if the information transmitted by the sender (Alice) to the receiver (Bob) during the key distribution process is intercepted by an eavesdropper (Eve), traces of the interception will remain in the information received by the receiver (Bob), and through this, the receiver (Bob) can know that the information has been intercepted.

[0201] The general operation of the BB84 protocol is as follows.

[0202] 1) The transmitting end (Alice) determines two random bit sequences associated with bit information and polarizer information, respectively. At this time, the polarization results of the bits according to the polarizer are as shown in [Table 3] below, and the correspondence relationship between the types of polarizers for the bits constituting the random bit sequence associated with the polarizer information is as shown in [Table 4] below.

[0203] Cross diagonal 0- / 1|\

[0204] 0 cross shape 1 diagonal

[0205] Referring to [Table 4], when a bit at a specific position constituting a random bit sequence related to polarizer information is 1, a specific bit included in the random bit sequence related to bit information corresponding to the bit at the specific position among the bits constituting the random bit sequence related to bit information can be polarized on a diagonal polarizer.2) Based on two determined random bit sequences, the transmitter polarizes the bit sequence related to bit information onto a polarizer determined based on the bit sequence related to polarizer information, and transmits the acquired polarized photons to the receiver (Bob). 3) The receiver (Bob) measures the photons transmitted from the transmitter (Alice) using an arbitrary polarizer. At this time, some of the photons transmitted by the transmitter (Alice) may be lost due to factors such as noise in the quantum channel, and accordingly, the receiver (Bob) may not be able to receive some of the photons.

[0206] As described above, after the process of transmitting quantum information through the quantum channel is completed, the sender (Alice) and the receiver (Bob) perform a post-processing step to share the same secret key through the public channel.

[0207] 4) The receiver (Bob) transmits information to the transmitter (Alice) about which photon it has received and also provides information about the polarizing plate at that location. At this time, the transmitter (Alice) also provides information about the polarizing plate at the location corresponding to the photon received by the receiver (Bob).

[0208] 5) Based on the polarizing plate information exchanged between them, the transmitter (Alice) and the receiver (Bob) obtain bit values ​​corresponding to bit positions where the same polarizing plate is used. The receiver (Bob) discloses only some of the obtained bit values ​​to the transmitter (Alice). If the sequence disclosed by the receiver (Bob) is the same as the bit value transmitted by the transmitter (Alice), the remaining sequence not disclosed by the receiver (Bob) is used as a secret key. Here, if the same polarizing plate is used for photon transmission by the transmitter (Alice) and photon reception by the receiver (Bob), respectively, the information transmitted by the transmitter (Alice) and the information received by the receiver (Bob) will be the same. If the information transmitted by the transmitting end (Alice) and the information received by the receiving end (Bob) differ even though the same polarizer was used for photon transmission by the transmitting end (Alice) and photon reception by the receiving end (Bob), it can be determined that eavesdropping has occurred based on the ratio of the information with different values ​​among all information for which the same polarizer was used.

[0209] The BB84 Protocol, the quantum key distribution method described above, is schematically explained as shown in Fig. 14. Fig. 14 illustrates an example of a quantum key distribution procedure according to the BB84 Protocol.

[0210] 1. The sender Alice first selects a basis for the message to generate a key. (Quantum basis Selection R) The basis may be randomly chosen with pure random characteristics such as QRNG, or it may be selected as a specific basis by Alice's choice.

[0211] 2. The sender generates classical message information to be used for key generation and stores it later for symmetric key generation with the receiver. (Message M) The classical message to be used for key generation may be randomly chosen with pure random characteristics such as QRNG, or it may be written as a specific message by Alice's choice.

[0212] 3. The transmitter generates a quantum state to be transmitted through the quantum channel based on the previously selected basis and classical message information for key generation, and then transmits it to the receiver through the quantum channel. (Quantum State R(M))

[0213] 4. The receiver Bob first selects a basis for key measurement. (Measurement Basis Selection R') The basis may be randomly chosen with pure random characteristics such as QRNG, or it may be selected as a specific basis by Bob's choice.

[0214] 5. The receiver measures the key generation information received through the quantum channel based on the selected basis and stores the measurement result. (Measured Message M')

[0215] 6. The receiver feeds back to the transmitter the location of the selected information (Selected Index), the measurement basis (Basis), and the measurement result (Result) for estimating the Quantum Bit Error Rate (QBER) for security verification. Additionally, it feeds back to the transmitter the basis used to measure the entire message. (Measurement Basis Feedback R')

[0216] 7. To estimate the feedback QBER, the transmitter calculates the Error Rate by comparing the measurement results (Result) in cases where the measurement basis matches at the location index of the information selected by Bob with the message it generated. (QBER Estimation)

[0217] 8. The transmitter checks whether the error rate exceeds a predefined QBER threshold. If the error rate is lower than the QBER threshold, it is determined that there is no eavesdropper in the key transmission, and if not, it is determined that it has been attacked by an eavesdropper.

[0218] 9. If the transmitter determines that there are no eavesdroppers on the key transmission, it transmits the locations of information that match the basis of the receiver to the receiver via the classical channel. (Matched Basis Index)

[0219] 10. The sender and receiver utilize messages corresponding to locations of information with matching bases as a key. (Key Sifting)

[0220] 11. The transmitting and receiving units can perform secure communication using the generated Sifted Key, or generate and utilize a high-purity key through post-processing.

[0221] (2) Post-processing of quantum key distribution

[0222] The post-processing of quantum key distribution is a process that resolves discrepancies between the sender and receiver's cryptographic keys caused by eavesdropping attacks or imperfections in the quantum channel and quantum detection device. Through this post-processing, identical key information between the sender and receiver is guaranteed, and at the same time, the correlation between exposed information and key information can be reduced to prevent eavesdroppers from inferring key information from the exposed data. This post-processing consists of information reconciliation, privacy amplification, and authentication processes.

[0223] 1) Information correction

[0224] Information correction is a process that resolves discrepancies between a sender and a receiver caused by various factors, ensuring that they possess identical information. In other words, it is identical to the error correction process in mobile communication that rectifies errors in receiver information. However, unlike conventional mobile communication where information is pre-encoded for error correction, correction is performed through additional information transmission after the encryption key transmission between the sender and receiver is completed. Since this additional information transmission takes place via a public channel with a zero error rate—similar to a typical internet environment—a problem may arise where a certain amount of information is exposed to eavesdroppers; therefore, protocols exist to address this issue. A representative example of an information correction protocol is the Cascade protocol, which consists of a binary search algorithm and a traceback algorithm and is characterized by being executed iteratively over multiple stages.

[0225] 2) Amplification of secrecy

[0226] Confidentiality amplification is a process that reduces the correlation between the information possessed by an eavesdropper and the cryptographic key information. As previously explained, a certain amount of information is exposed to the eavesdropper during the information correction process used to rectify errors in the cryptographic key. In other words, since an eavesdropper can obtain a certain amount of information regarding the cryptographic key, the amount of exposed information is removed from the key data to ensure perfect security. Because the additional information used to correct errors during the information correction process for the cryptographic key shared between the transmitter and receiver is exposed to the eavesdropper, only a portion of the key retains perfect secrecy. Therefore, confidentiality amplification can also be understood as a process of refining information so that the cryptographic key shared between the transmitter and receiver can maintain perfect secrecy. A representative example of confidentiality amplification is Universal Hashing, which operates based on the property that for any two different input values ​​x and y, the probability g(x) = g(y) is maximized (where m is the size of the hash function range). The characteristics of universal hashing can significantly reduce the probability that an eavesdropper can guess the encryption key.

[0227] 3) Certification

[0228] Authentication is not a process unique to quantum key distribution, but is necessary to counter man-in-the-middle attacks by eavesdroppers. A man-in-the-middle attack occurs when an eavesdropper intercepts information transmitted by a sender, alters it, and re-transmits the altered information to the receiver. Due to man-in-the-middle attacks, the receiver must verify that the received information was sent from the correct sender. To this end, a hash function is predefined between the sender and receiver, and the sender uses this hash function to generate a hash tag for the cryptographic key and transmits it to the receiver along with the key. Subsequently, the receiver inputs the received cryptographic key into its own hash function and checks if the generated hash tag matches the hash tag transmitted by the sender, thereby confirming that the sender is the legitimate sender. The authentication process is performed concurrently with all post-processing steps of key distribution; specifically, information transmission between the sender and receiver proceeds alongside authentication during the information correction and secret amplification processes.

[0229] Quantum Direct Communication (QDC)

[0230] Quantum Direct Communication shares similarities with Quantum Key Distribution (QKD), which is used as a 4 / 5G secure communication technology, in that it is a technique for securely transmitting classical message information. However, while QKD is a method of sharing symmetric secret key information, which is necessary to securely transmit message information sent over a classical channel, between the sender and receiver via a quantum channel using the quantum mechanical property of being unclonable, QDC differs in that it is a method of sharing classical message information to be transmitted directly via a quantum channel, rather than a secret key.

[0231] Quantum secure direct communication (QSDC) is a group of QDC technologies that has the advantage of ensuring high security by not generating leakage information related to transmitted information, and can be broadly classified into DL04 QSDC and Two-step QSDC techniques that use a single photon light source and an entangled light source, respectively.

[0232] (1) DL04 QSDC protocol

[0233] FIG. 15 illustrates an example of a protocol for dL04 QSDC according to one embodiment of the present disclosure. The single-photon-based dL04 QSDC technique is a technique for directly transmitting a message (information) to be transmitted through a quantum channel, and 1 bit of classical information per photon can be transmitted. Referring to FIG. 15, the dL04 QSDC protocol in which the dL04 QSDC technique is performed may be composed of a transmitter-receiver (Alice, Bob), a quantum channel, and a classical channel.

[0234] In step S1401, the receiver (Bob) constructs a single-photon train based on polarization information. Each single photon included in the constructed single-photon train can be generated randomly into one of the four states of [Equation 3] below.

[0235]

[0236] The single photon train generated in the state of [Equation 3] is used by the receiver (Bob) to transmit information about the initial quantum state to the transmitter (Alice).

[0237] In step S1403, the receiver (Bob) transmits information about the initial quantum state based on the generated single-photon train to the transmitter (Alice). At this time, some of the information about the initial quantum state can be used to estimate the quantum bit error rate (QBER).

[0238] In step S1405, the transmitter (Alice) determines whether eavesdropping has occurred. The receiver (Bob) transmits position information to be used for QBER estimation to the transmitter (Alice) via the classical channel, and the transmitter (Alice) performs measurements by randomly selecting an orthogonal or diagonal basis for some of the information used for QBER estimation based on the position information among the single photons included in the received single photon train. At this time, the transmitter (Alice) transmits measurement information regarding the basis used for measurement and the value of the measured information to the receiver (Bob), and the receiver (Bob) calculates the QBER by comparing the received information with the information it initially generated, limited to information where the same basis was used among the received information, and determines whether eavesdropping has occurred. If the QBER value is higher than the threshold value for determining eavesdropping, the receiver (Bob) determines that the quantum channel is unsafe and stops communication. Conversely, the receiver (Bob) may perform subsequent operations.

[0239] In step S1407, the transmitter (Alice) performs encoding. If the transmitter (Alice) determines that there is no eavesdropper based on the QBER estimation result, it encodes the message (information) to be transmitted based on the remaining single-photon sequence, excluding the single-photon used for QBER estimation from the total single-photon sequence received in step S1403. Encoding can be performed in various ways. According to one embodiment, encoding can be performed through an identity operation denoted by I, which causes no change when the information contained in the message is 0, and through a unitary operation defined by U when the information is 1. Here, the unitary operation can be performed as shown in [Equation 4] below.

[0240]

[0241] In steps S1409 through S1413, the transmitter (Alice) transmits a sequence of single photons that has been encoded to the receiver (Bob). To do this, the transmitter (Alice) may perform modulation, and the transmitter (Bob) may perform demodulation. The receiver (Bob) measures each single photon using the same basis information as the initial measurement basis to read a message (information) from the transmitted sequence of single photons. Some of the information from the same basis information as the initial measurement basis is used for QBER estimation, and the receiver (Bob) may receive the position of the photon and the value of the encoding bit to be used for QBER estimation from the transmitter (Alice) over a public channel.

[0242] In step S1415, the receiver (Bob) determines the values ​​of parameters to be used for decoding based on the measured QBER value and can perform decoding for the received message.

[0243] Through steps S1401 to S1415, the QSDC technique enables the secure transmission of message information generated by the transmitter to the receiver via a quantum channel. Specifically, the transmitter performs QBER estimation on the initial state generated by the receiver and, based on the QBER estimation, verifies whether the initial state is safe from eavesdroppers; thus, message information can be encoded into an initial state that is guaranteed to be safe from eavesdroppers. Consequently, even if an eavesdropper exists in the backward quantum channel, the eavesdropper, who does not know the value of the initial state, cannot obtain meaningful message information from the encoded message even if they intercept it, thereby ensuring security.

[0244] The single-photon-based QSDC technique described in Fig. 15 can enable communication with high security without using a quantum secret key, but it has limitations in that it only allows the transmission of classical information at a rate of 1 bit per photon, and the maximum data rate cannot exceed the maximum detection speed of the single photon detector (SPD) due to the dead time of the SPD. In a quantum information transmission system, the transmitter typically generates a quantum state to be transmitted based on the properties (characteristics) of the photon, attenuates the signal to the single-photon level through a signal attenuator (VOA), and transmits it to the receiver over a quantum channel. Here, the properties (characteristics) of the photon may include polarization, phase, time information, etc. The receiver detects the signal transmitted by the transmitter using a single-photon detector. At this time, information transmitted via photons may not be fully detected at the receiver due to various factors, and loss may occur. These various factors may include channel-related losses and the low measurement accuracy of the SPD. In particular, if the signal generation rate from the light source (LD) exceeds the maximum signal detection rate of the detector, the loss of the received signal may increase further. Such loss of the received signal may be caused by dead time, which is the time required for the SPD to return to a ready state to detect the next signal (photon) after detecting a signal at a specific point in time. Here, dead time refers to the time during which no signal is detected by the SPD while the detector is turned off and recharged, following the occurrence of avalanche breakdown based on the generation and emission of numerous electrons and holes caused by the influx of light.

[0245] (2) Two-step Quantum Security Direct Communication (two-step QSDC) protocol

[0246] Two-stage quantum secure direct communication can be performed based on super dense coding techniques.

[0247] Super dense coding is a technique that can safely transmit classical information using quantum communication, and is a technique that can stably transmit 2 bits of classical information using four types of single entangled photons (EPR-pairs) of [Equation 5] below.

[0248]

[0249] When using super-dense coding, the transmitter can transmit 2 bits of classical information to the receiver via a quantum channel using a single qubit. First, two qubits in an entangled state are generated. The transmitter possesses the first qubit in the entangled state, and the receiver possesses the second qubit in the entangled state. There are four possible cases for the qubit that the transmitter intends to transmit: '00', '01', '10', and '11'. For these four cases, the transmitter performs a qubit operation corresponding to each of the four cases on the entangled qubit it possesses, and then transmits the result through the quantum channel. At this time, the qubit operation can be expressed in the form of I, Z, X, and iY. Each operation performed by the transmitter can serve to change the entangled state shared by the transmitter and the receiver into a different basis form that is orthogonal to each other. Therefore, the receiver measures the qubit it possesses to recover the 2 bits of information transmitted by the transmitter.

[0250] FIG. 16 illustrates an example of a procedure for transmitting quantum information in a two-stage quantum secure direct communication according to one embodiment of the present disclosure. In FIG. 16, SR 1 through SR 4 are optical delay lines that serve as quantum memories. CE (checking eavesdropping) 1 and CE 2 are devices for checking the presence of an eavesdropper. CM (coding message) is a device for encoding classical message information to be transmitted from the first device (1610) to the second device (1620). EPR source is a device for generating an entangled light source in an EPR state, and bell state measurement measures entangled photon pairs.

[0251] In 2-stage quantum secure direct communication, unlike superdense coding, entangled photon pairs are not transmitted all at once to ensure security; instead, they are divided into two stages and transmitted through an upper quantum channel and a down quantum channel. For an eavesdropping session on an entangled light source, an eavesdropper must know the information from both ends of the entangled photon pair to determine the transmitted information through measurement. To prevent eavesdropping, 2-stage quantum secure direct communication utilizes a method where one end of the entangled photon pair is transmitted first, and its security against eavesdropping is verified. Once security is guaranteed, the remaining part of the photon pair, which contains the message information to be sent, is then transmitted.

[0252]

[0253] Specific embodiments of the present disclosure

[0254] The present disclosure relates to the generation of quantum keys in a wireless communication system and to a technique for sharing quantum keys between two nodes. Specifically, the present disclosure proposes a technique to overcome the disadvantages of existing quantum key exchange procedures. The present disclosure proposes various embodiments for performing quantum key exchange having basis independence.

[0255]

[0256] In a communication network system, the Diffie-Hellman (DH) key exchange method can be used to generate a symmetric key between two nodes. For example, the Diffie-Hellman (DH) key exchange method can be used as one of the key exchange procedures for generating a session key in transport layer security, and the DH key exchange method can be used as a key exchange procedure in the Internet key exchange (IKE) procedure to support network layer security. DH key exchange is a method of exchanging cryptographic keys that allows two people to share a common secret key over an unencrypted communication network. If any two nodes are referred to as Alice and Bob, Alice and Bob perform a procedure as shown in FIG. 17 to perform DH key exchange over an open communication network. FIG. 17 illustrates an example of a DH key exchange procedure.

[0257] Referring to Fig. 17, Alice and Bob perform the following actions.

[0258] 1) Alice selects a prime number p and an integer g smaller than p, and shares them with Bob in advance.

[0259] 2) Alice selects a random integer a. This integer is not disclosed externally, and Bob does not know it either.

[0260] 3) Alice , in other words Calculate the remainder when divided by p.

[0261] 4) Similarly, select an arbitrary integer b Calculate.

[0262] 5) Alice and Bob send A and B to each other.

[0263] 6) Alice Calculate, and the rice Calculate.

[0264] In the final stage = = And, = = and therefore Alice and Bob are They come to share a common secret key s. Only Alice and Bob know a and b, and g, p, , Only can be known.

[0265] Here, if p is sufficiently large, Eve, an eavesdropper who is eavesdropping to find out the secret key from the outside, me It is known that s cannot be determined through [this method]. Since Alice and Bob have acquired a secret key s known only to the two of them, they can encrypt future communications using symmetric key cryptography. However, if p, a, or b are too small, an eavesdropper can calculate s by trying all possible combinations. Therefore, sufficiently large prime numbers must be used for actual secret communication. It is known that if p is a prime number of at least 300 digits and a and b are integers of at least 100 digits each, the secret key cannot be determined from publicly available information even by mobilizing all the computers currently possessed by humanity.

[0266] However, advancements in quantum computer technology and quantum algorithms have brought threats to the security of key exchange methods based on the Discrete Logarithm Problem (DLP). It is theoretically established that encryption methods based on RSA (RIVEST-SHAMIR-ADLEMAN) or ECC (Elliptic Curve Cryptography), which are generally symmetric key generation algorithms used in DH key exchange and asymmetric key-based security systems, can be deciphered within the validity period through the parallel computation of the Shor Algorithm. In the case of RSA 2048-bit, factoring is possible within 8 hours using 20 million noisy qubits, and factoring was even revealed within 177 days using only 13,436 qubits based on multi-parallel quantum memory. The collapse of DLP-based encryption systems by such quantum algorithms poses a serious threat to secure communication systems based on DH or asymmetric key encryption.

[0267] To prevent such security threats, a method capable of addressing the threats posed by quantum algorithms is required. While post-quantum cryptography (PQC) technology is emerging, all systems based on computational complexity inevitably face the risk of being threatened by the emergence of new quantum algorithms. Furthermore, transitioning to a new security system can entail a significant technical burden to implement the new security technology across the entire device. Similarly, as PQC is a security method based on computational complexity, it cannot achieve physical security. Therefore, even if real-time leakage does not occur, an attacker can subsequently perform a plaintext attack through Harvest-Now-Decrypt-Later (HNDL) attacks.

[0268] To address this, quantum key distribution (QKD) or two-way quantum key exchange (QKE) methods, which utilize quantum properties in the key distribution procedure, can be considered. In the case of QKD, Alice and Bob share the symmetric key through asymmetric procedural characteristics, as their procedures have different structures. Conversely, the two-way QKE method shares the symmetric key through symmetric procedural characteristics, as Alice and Bob have identical procedures.

[0269]

[0270] Two-way QKE method

[0271] FIGS. 18a and 18b illustrate the overall protocol flow of a bidirectional QKE method based on symmetric procedural characteristics. In the protocol exemplified in FIGS. 18a and 18b, the quantum channel used for the qubit stream transmitted from Alice to Bob is referred to as Quantum Channel #1, and the quantum channel used for the qubit stream transmitted from Bob to Alice is referred to as Quantum Channel #2.

[0272] Stage 1: Quantum Key Exchange

[0273] Alice is Secret Key Sequence and quantum basis sequence Generates and the Initial Quantum Key Stream in a quantum state It generates. Specifically, Alice randomly generates L predefined secret key values. Additionally, Alice randomly generates an Alice basis of a predefined length L. For example, the secret key sequence is , As such, Alice base , It can be generated as follows. Here, the underlying information can be represented in bits. For example, , Alice's Initial Quantum Key is the initial qubit state Unitary operation by secret key on the state is applied, and unitary operation based on the Alice basis It has a quantum state to which is applied. Here, unitary operation It can be expressed as a phase rotation or polarization rotation with respect to a quantum state. The unitary operations mentioned in this disclosure are not limited to the manner described above. The unitary operations mentioned in this disclosure are operations to which the commutative property can be applied between operations. For example, an initial quantum key: , It can be generated as follows. Specifically, the initial quantum key is , It can be generated as follows.

[0274] Bob is a secret key sequence and quantum basis sequence Generates and initial quantum key stream in a quantum state It generates. Specifically, Bob randomly generates L predefined secret key values. And, Bob randomly generates a basis of a predefined length L. For example, the secret key sequence is , As such, the rice base , It can be generated as follows. Here, the underlying information can be represented in bits. For example, , is. Bob's initial quantum key is the initial qubit state Unitary operation by secret key on the state is applied, and unitary operation based on Bob Basis It is a quantum state to which is applied. Here, unitary operation As such, it may mean phase rotation or polarization rotation with respect to a quantum state. The unitary operations mentioned in this disclosure are not limited to the manner described above. The unitary operations mentioned in this disclosure are operations for which the commutative law can be applied between operations. For example, an initial quantum key: , It can be generated as follows. Specifically, the initial quantum key: , It can be generated as follows. And, Alice and Bob through the initial quantum key streams via each quantum channel and Transmits.

[0275]

[0276] Stage 2: Secret Key Encoding and Basis Compensation

[0277] Alice and Bob encode their secret keys into the quantum states received through each quantum channel. For example, Alice As such, rice is Perform encoding as follows.

[0278] Alice and Bob receive through their respective quantum channels and base compensate the received quantum states with their own bases for the quantum states that encode their secret keys. The Alice measurement basis for Alice's basis compensation is is, Performing base compensation It is defined as. For example, and, specifically, It could be.

[0279] The measurement basis of rice for the basis compensation of rice is is, Performing base compensation It is defined as. For example, and, specifically, It could be.

[0280] Alice and Bob measure each qubit stream with a Z measure. In Alice, the measured value of quantum channel #2 is And, the measured value of Quantum Channel #1 in rice: It could be.

[0281]

[0282] Stage 3: Quantum Basis Matching and QBER Testing

[0283] Alice and Bob reveal their measurement bases to each other through the classic channel. For example, Alice tells Bob Alice's measurement base Sends, and Bob tells Alice Bob's measurement basis Transmits.

[0284] Alice and Bob compare the other party's measurement basis received from the other party with the basis they used when transmitting, and Basis Matching information It stores. For example, the basis matching in Alice and Bob is It can be performed as follows. Here, and is a basis vector represented in bits. For example, , am.

[0285] Alice and Bob are underlying matching information Based on this, random selection is performed on indices equal to the number of qubits for the QBER check from among the base-matched qubit indices. The random selection among the base-matched qubit indices is It involves selecting an arbitrary index from among the indices. For example, Alice's random qubit index selection is , Bob's random qubit index selection is It can be expressed as follows.

[0286] Alice and Bob separately store secret key information for randomly selected qubit indices for QBER verification. For example, Alice's randomly selected qubit value is And, the randomly selected qubit value of Bob is It may include.

[0287] Alice and Bob transmit a randomly selected index and qubit value for a QBER check to each other via a classical channel. Alice sends to Bob , Sends. Bob to Alice , Transmits.

[0288] Alice and Bob each perform a QBER test based on the information related to the QBER test received from the other and the information they themselves measured. Since each of them is comparing measurements against an index selected by the other, Alice and Bob perform the QBER test after compensating for their own positive encoding. For example, Alice, the qubit index selected by Bob Regarding, the measured value that one measured to your secret key Compensated by XORing, and the qubit value information of Bob transmitted by Bob XOR it again to check for a match. Since is a vector composed of indices, the above operation is performed on all element indices, and then a match is checked. The entire The number of mismatches relative to the number of indices becomes the QBER value. Alice and Bob are at the predefined QBER threshold. Each person checks if the QBER check Value exceeds, and the threshold It is judged as ACK if it does not exceed, and NACK if it exceeds. The QBER check for Quantum Channel #2 in Alice is It is performed as follows. In the same way, Bob also performs a QBER test. The QBER test for Quantum Channel #1 in Bob is It is performed as follows. Alice and Bob transmit the ACK / NACK result of the QBER check to the other party through the classical channel.

[0289]

[0290] Stage 4: Key Acquisition and Post-processing

[0291] Alice and Bob perform key shifting when both their QBER checks are ACKs. If either Alice or Bob's QBER check is NACK, they discard all measured keys and initialize the bidirectional QKE protocol.

[0292] Alice and Bob obtain the symmetrically shifted key that is not used in QBER from among the basis-matched measured keys. Basis-matched measured keys Among them, a symmetrically shifted key is obtained using the measurement value of a qubit not used in QBER. For example, the basis-matched measured key When saying that, the qubit used in QBER is Since it corresponds to, is the set of indices of qubits not used in QBER. Therefore, Alice's key shifting is It can be obtained through and is used as a symmetrically shifted key. Similarly, Bob's key shifting is It can be obtained through and is used as a symmetrically shifted key.

[0293] Alice and Bob perform separate post-processing via the classical channel to enhance key reliability. For example, separate operations such as error correction and privacy amplification for shifted keys are performed.

[0294] The bidirectional QKE operation through the aforementioned operation can be summarized as shown in [Table 5] below. In [Table 5], the qubit sequence length L=12.

[0295] Index123456789101112CH1(Alice) Tx Basis (B a (i))+×+×+×+×+×+×(Alice) Key (a(i))001100110011(Bob) Rx Basis (B b (i))+××++×+××+×+(Bob) Measure (m b (i))111001000101CH2(Bob) Tx Basis (B b (i))+××++×+××+×+(Bob) Key (b(i))110001110010(Alice) Rx Basis (B a (i))+×+×+×+×+×+×(Alice) Measure (m a (i))110101000110Basis Matching○○NN○○○○NNNNNRandom Selection from Alice(for QBER Check)√√√Random Selection from Bob(for QBER Check)√√√Alice's Sifted Key (m a(i))0Bob's Sifted Key (m b (i))0

[0296]

[0297] In the aforementioned example, since Quantum Channel #1 from Alice to Bob and Quantum Channel #2 from Bob to Alice use the same basis pattern, basis matching occurred at indices 1, 2, 5, 6, 7, and 8, while no basis matching occurred at the remaining indices. Among the six indices where basis matching occurred, indices 1, 2, and 8 were randomly selected for Alice's QBER test, and indices 6, 7, and 8 were randomly selected for Bob's QBER test. Through this, Quantum Channel #1 performed a QBER test from Bob using indices 1, 2, and 8 selected from Alice. Similarly, Quantum Channel #2 performed a QBER test from Alice using indices 5, 6, and 7 selected from Bob. Since qubit index 5 is the only one among the six basis-matched indices that was not used for the QBER test, each measurement value for qubit index 5 With this, both Alice and Bob obtain the same symmetrically shifted key '0'.

[0298] The aforementioned bidirectional QKE has a problem in that, because Alice and Bob individually perform random selections for QBER checks on the index where base matching has occurred, the rate of shifted keys to be used as symmetric keys after the QBER check decreases, and the key rate also fluctuates depending on the selection. To solve this, it is necessary to make Alice and Bob's random selections identical. However, if a selection rule is determined in advance, the attacker Eve can evade the QBER check based on this, increasing the probability of key leakage and causing security issues. To resolve this, the QBER procedure of Stage 3 can be modified as shown in FIGS. 19a and 19b. The procedure below, excluding the QBER procedure of Stage 3, is identical to the existing procedure described above.

[0299] Figures 19a and 19b illustrate the overall protocol flow of different bidirectional QKE methods based on symmetric procedure characteristics.

[0300] Stage 1 and Stage 2

[0301] It is the same as the operation described with reference to FIGS. 18a and FIGS. 18b.

[0302] Stage 3: Quantum Basis Matching and QBER Testing

[0303] Alice and Bob disclose their measurement bases to the other party via a classical channel. Alice and Bob compare the other party's measurement base received from them with the base they used when transmitting to obtain base matching information. Stores. The node with the authority to select the qubit between Alice and Bob has the basis matching information Based on this, indices equal to the number of qubits for the QBER check are randomly selected from the base-matched qubit indices. The selection of the node with qubit selection authority can be determined by a predefined rule or designated in real-time via separate signaling. For example, qubit selection authority can be set by pre-defining an operation expression based on the identification of Alice and Bob, such as their Network IDs or IPs. For instance, the node with the smaller ID value holds the authority. The random selection among the base-matched qubit indices is Selecting an arbitrary index from the indices can be expressed as follows. If the node with the authority to select qubits is Alice, the selection of a random qubit index is It is performed as follows.

[0304] If Alice is the node with the authority to select qubits, Alice separately stores secret key information for randomly selected qubit indices for QBER verification. Alice's randomly selected qubit value is It can be expressed as follows.

[0305] Alice sends a randomly selected index and qubit value for a QBER check to Bob via the classical channel. For example, Alice sends to Bob , Sends. Bob is a randomly selected qubit index from Alice. Upon receiving, the secret key information corresponding to the qubit index is sent to Alice. For example, Bob sends to Alice , Transmits.

[0306] Alice and Bob each perform a QBER test based on the information related to the QBER test received from the other and the information they have measured. Since the comparison involves the measurements of each channel against the index selected by Alice, Alice and Bob each perform the QBER test after compensating their own Quantum Encoding. For example, in the case of Alice, the qubit index selected by her Regarding, the measured value that one measured to your secret key XOR to compensate, and the qubit value information of Bob transmitted by Bob XOR it again to check for a match. Since is a Vector composed of indices, the above operation is performed on all element indices, and then a match is checked. The entire The number of mismatches relative to the number of indices becomes the QBER value. Alice and Bob are at the predefined QBER threshold. Each checks if it exceeds the QBER check value, and the threshold It is judged as ACK if it does not exceed, and NACK if it exceeds. The QBER check for Quantum Channel #2 in Alice is It can be performed as follows. Similarly, Bob is also the qubit index selected by Alice. For this, a QBER test is performed. The QBER test for Quantum Channel #1 in Bob is It can be performed as follows. Alice and Bob send the ACK / NACK result of the QBER check to the other party through the classical channel.

[0307] Stage 4: Key Acquisition and Post-Processing

[0308] Alice and Bob perform key shifting when both their QBER checks and their own are ACKs. If either Alice or Bob's QBER check is NACK, they discard all measured keys and initialize the bidirectional QKE protocol.

[0309] Alice and Bob obtain the symmetrically shifted keys that are not used in QBER among the basis-matched measured keys. Basis-matched measured keys Among them, a symmetrically shifted key is obtained using the measurement value of a qubit not used in QBER. For example, the basis-matched measured key When saying that, the qubit used in QBER is Since it corresponds to, is the set of indices of qubits not used in QBER. Therefore, Alice's key shifting is It can be obtained through and is used as a symmetrically shifted key. In the same way, Bob's key shifting is It can be obtained through and is used as a symmetrically shifted key.

[0310] Alice and Bob perform separate post-processing via a classical channel to enhance key reliability. For example, error correction for shifted keys and privacy amplification can be performed as separate operations.

[0311] The bidirectional QKE operation through the aforementioned operation can be summarized as shown in [Table 6] below. In [Table 6], the qubit sequence length L=12.

[0312] Index123456789101112CH1(Alice) Tx Basis (B a (i))+×+×+×+×+×+×(Alice) Key (a(i))001100110011(Bob) Rx Basis (B b (i))+××++×+××+×+(Bob) Measure (m b(i))111001000101CH2(Bob) Tx Basis (B b (i))+××++×+××+×+(Bob) Key (b(i))110001110010(Alice) Rx Basis (B a (i))+×+×+×+×+×+×(Alice) Measure (m a (i))110101000110Basis Matching○○NN○○○○NNNRandom Selection(for QBER Check)√√√Alice's Sifted Key (m a (i))010Bob's Sifted Key (m b (i))010

[0313]

[0314] In the above example, since Quantum Channel #1 from Alice to Bob and Quantum Channel #2 from Bob to Alice use the same basis pattern, basis matching occurred at indices 1, 2, 5, 6, 7, and 8, while no basis matching occurred at the remaining indices. From the six indices where basis matching occurred, randomly selected indices 1, 2, and 8 were chosen for Alice's QBER test. Through this, Quantum Channel #1 performed a QBER test from Bob using the indices 1, 2, and 8 selected by Alice. Since Bob follows Alice's selection, Quantum Channel #2 also performed a QBER test from Alice using the indices 1, 2, and 8 selected by Alice. Among the six basis-matched indices, the qubit indices 5, 6, and 7 were not used for the QBER test; therefore, for each measurement value for qubit indices 5, 6, and 7 With this, both Alice and Bob obtain the same symmetrically shifted key '[0,1,0]'.

[0315] In the above bidirectional QKE, since Alice and Bob perform a random selection for the QBER check on the index where base matching has occurred, the rate of the shifted key to be used as a symmetric key does not decrease after the QBER check; however, signaling or configuration rules for setting the selection authority must be agreed upon, which results in the two nodes not having the same authority. Furthermore, a node without selection authority cannot transmit information for the QBER check to the other party until it receives random selection information from the node with selection authority. Consequently, sequential signaling is required in the protocol procedure, leading to a problem of protocol delay.

[0316] Consequently, bidirectional QKE has the problem of having to use symmetric procedures that result in a reduction in the key rate or asymmetric procedures that result in protocol delay. Therefore, the present disclosure proposes a method for improving the protocol performance of bidirectional QKE through basis independence characteristics and logical encoding.

[0317] The technique according to an embodiment of the present disclosure may be referred to as a bidirectional QKE (Quantum Key Exchange) with basis independence. The present disclosure proposes a method for constructing a symmetric protocol without loss of key rate in a procedure for sharing a symmetric key through a bidirectional QKE based on quantum properties.

[0318]

[0319] The objectives of the proposed technology are, first, that two nodes sharing a symmetric key must maintain a symmetric protocol that performs the same procedure simultaneously; second, that the presence or absence of an attacker must be verified through inspection of the quantum channel; third, that there must be no leakage of the transmitted message by making repeated measurement impossible through the transmission of security information via the quantum state; and fourth, that subsequent plaintext attacks must be made impossible even against an attacker's HNDL (Harvest-Now-Decrypt-Later) attack based on the coherent time characteristics of the quantum.

[0320] The proposed technology ensures that the transmit quantum basis and the measurement quantum basis of each node are independent, and based on this, a qubit selection rule for QBER checks is established so that qubit selection is not performed randomly. In addition, the encoding of the security key and / or secret key is not performed in the quantum state, but is performed using logical encoding during the step of deriving the shifted key, thereby minimizing the impact of errors in the quantum gate. The core protocol flow of the bidirectional QKE method based on the proposed symmetric procedural characteristics is as shown in FIGS. 20a and 20b.

[0321]

[0322] FIGS. 20a and 20b illustrate examples of procedures for exchanging keys based on a bidirectional QKE scheme having basis independence according to one embodiment of the present disclosure. In the protocols illustrated in FIGS. 20a and 20b, the quantum channel used for the qubit stream transmitted by Alice to Bob is referred to as quantum channel #1, and the quantum channel used for the qubit stream transmitted by Bob to Alice is referred to as quantum channel #2.

[0323] Stage 1: Quantum Key Exchange

[0324] Alice is a security key sequence (e.g., secret key sequence) and transmitted quantum basis sequence Generate and an initial quantum key stream in a quantum state (e.g., initial quantum key stream) Generates. For example, Alice randomly generates L predefined security key values. For example, the security key sequence or secret key sequence is , It can be. And, Alice randomly generates L basis values ​​such that the Alice transmit basis has a predefined length L. For example, Alice's transmit basis is , It can be. Here, the basis information can be represented by being digitized. For example, the basis information , am.

[0325] Alice's initial quantum key is the initial qubit state Unitary operation by secret key is applied, and unitary operation by Alice's transmission base It has a quantum state to which is applied. Here, the unitary operation is As such, it may mean phase rotation or polarization rotation with respect to a quantum state. However, the unitary operations mentioned in this disclosure are not limited to the manner described above. The unitary operations mentioned in this disclosure are operations to which the commutative law can be applied between operations. For example, the initial quantum key is , It could be. As a specific example, the initial quantum key is , It could be.

[0326] Bob is a secret key sequence and transmitted quantum basis sequence Generates and initial quantum key stream in a quantum state It generates. For example, Bob randomly generates L predefined secret key values. For example, the secret key sequence is , It can be. And, Bob randomly generates L basis values ​​such that the Bob transmitting basis has a predefined length L. For example, Bob's transmitting basis is , is. Here, the underlying information can be represented in bits. For example, , am.

[0327] Bob's initial quantum key is the initial qubit state Unitary operation by secret key is applied, and unitary operation based on the transmission base of rice It has a quantum state to which is applied. Here, unitary operation As such, it may mean phase rotation or polarization rotation with respect to a quantum state. The unitary operations mentioned in this disclosure are not limited to the manner described above. The unitary operations mentioned in this disclosure are operations for which the commutative law can be applied between operations. For example, the initial quantum key is , It could be. As a specific example, the initial quantum key is , It could be.

[0328] Alice and Bob through the initial quantum key streams via each quantum channel and Alice transmits the initial quantum key stream to Bob via Quantum Channel #1. Specifically, Alice transmits the initial quantum key stream to Bob via Quantum Channel #1. Bob transmits the initial quantum key stream to Alice via Quantum Channel #2. transmits.

[0329] Stage 2: Baseline Compensation and Measurement

[0330] Alice and Bob each base-compensate the received quantum state using their own measurement basis for the quantum state received through the quantum channel. Alice's measurement basis for basis compensation in Alice is is. In the present disclosure, Performing base compensation is It is expressed as. For example, Alice's measurement basis is , It can be. Here, the underlying information can be represented in bits. For example, , is. For example, It could be. As a specific example, It could be.

[0331] The measurement basis of rice for basis compensation in rice is is. In the present disclosure, Performing base compensation as is It is expressed as. For example, the measurement basis of rice is , It can be. Here, the underlying information can be represented in bits. For example, , It could be. Then, It can be. For example, It could be.

[0332] Alice and Bob measure each qubit stream with a Z measure. At this time, the measured value of Quantum Channel #2 in Alice is , It could be. The measured value of quantum channel #1 in rice is , It could be.

[0333] Stage 3: Quantum Basis Matching and QBER Testing

[0334] Alice and Bob each disclose their transmit base and measure base to the other via a classical channel. Alice tells Bob Alice's transmit base and Alice's measurement basis transmits. Bob sends Bob's transmission base to Alice. Measurement basis of wa and rice They transmit. Alice and Bob each compare the other party's measurement basis received from the other with their own transmission basis, and transmit basis matching information indicating the comparison result. and It generates. The basis matching information for Quantum Channel #1 by Alice is It could be. The basis matching information for quantum channel #2 by Bob is It could be. Here, and , and These are basis vectors represented in bits. For example, , And, , It can be. That is, basis matching information indicates whether there is a match between two bases based on their basis values. The basis matching information for Quantum Channel #1 by Bob is It could be. The basis matching information for Quantum Channel #2 by Bob is It could be. Here, and , and These are basis vectors represented in bits. For example, , And, , It can be. In other words, basis matching information indicates whether there is a match between two bases based on their basis values.

[0335] Alice is the basis matching information Based on, at least one test qubit for the QBER check is selected. And, Bob uses the basis matching information Based on this, a test qubit for the QBER inspection is selected. For Alice and Bob, basis matching is performed in the quantum channel they each transmitted ( ), where a basis matching was not achieved in the quantum channel transmitted by the other party ( ) A qubit can be selected as at least one qubit for QBER check. For example, the basis-matched index for quantum channel #1 transmitted by Alice is And, for Quantum Channel #2 transmitted by Bob, the index for which a basis matching was not achieved is In this case, Alice can determine the index of the qubit for the QBER check as follows. Alice's selection of the check qubit index is It can be performed as follows. For example, the basis-matched index for Quantum Channel #2 transmitted by Bob is And, for Quantum Channel #1 transmitted by Alice, the index for which basis matching was not achieved is In this case, Bob can determine the index of the qubit for the QBER check as follows. Bob's selection of the check qubit index is It can be performed as follows.

[0336] Alice and Bob each store secret key information for the qubit index selected by the aforementioned rule for QBER verification. Here, Alice's verification qubit value is Ro, Bob's inspection qubit value is It is expressed as such. Alice and Bob each transmit the index and value of at least one check qubit selected for QBER checking to the other party via a classical channel. That is, Alice to Bob and Send it, and Bob to Alice and It can transmit.

[0337] Alice and Bob each perform a QBER check based on information related to the QBER check received from the other party (e.g., the index and value of at least one check qubit) and information measured by themselves. For an index selected by the other party, Alice and Bob each perform a QBER check by comparing the secret key information transmitted by the other party with the measurement information they have measured. For example, Alice, the qubit index selected by Bob Regarding, the measured value by oneself and the qubit value of the rice received from the rice Check for a match by performing an XOR operation. Since it is a vector composed of indices, it is possible to check for a match after performing an XOR operation on all element indices. The entire The number of mismatches relative to the number of indices becomes the QBER value. Alice and Bob are the predefined QBER thresholds Check if each exceeds the QBER check value, and the threshold It is determined as ACK if it does not exceed, and NACK if it exceeds. In other words, the QBER check for Alice's Quantum Channel #2 is It can be performed as follows. Similarly, Bob also performs a QBER test. The QBER test for Bob's quantum channel #1 is It can be performed as follows.

[0338] Alice and Bob each transmit the ACK / NACK result of the QBER check to the other party through the classical channel. In other words, Alice feeds back the ACK or NACK result of the QBER check from Quantum Channel #2 to Bob. Bob feeds back the ACK or NACK result of the QBER check from Quantum Channel #1 to Alice.

[0339] Stage 4: Key Generation and Post-processing

[0340] Alice and Bob perform key shifting when the QBER check results for both Quantum Channel #1 and Quantum Channel #2 are ACK. If either Alice or Bob's QBER check, which is a security check for the two Quantum Channels, is NACK, Alice and Bob discard all measured keys and initialize the bidirectional QKE protocol.

[0341] Alice and Bob obtain a symmetrically shifted key by encoding the secret key for the measured key they each measured for an index where basis matching has been achieved for both quantum channels. Alice and Bob each have the index where basis matching has been achieved for both quantum channels as the symmetric key index, = It is defined as a symmetric key index. Measured height corresponding to Generates a shifted key by XORing its own secret key with it. For example, Alice's shifted key generation is It can be performed as follows. Bob's shifted key generation is It can be performed as follows. The shifted keys generated in Alice and Bob are As such, it is used as a symmetrically shifted key.

[0342] Alice and Bob perform separate post-processing via a classical channel to improve key reliability. For example, error correction and privacy amplification for shifted keys can be performed as separate processes.

[0343] Bidirectional QKE operations having underlying independence through the aforementioned operations can be summarized as shown in [Table 7] below. In [Table 7], the qubit sequence length L=12.

[0344] Index123456789101112CH1(Alice)Tx Basis (B a T (i))+×+×+×+×+×+×(Alice) Key (a(i))001100110011(Bob)Rx Basis (B b M (i))+××++×+××+×+(Bob) Measure (m b (i))001000110101CH2(Bob)Tx Basis (B b T (i))+×+××+××+×++(Bob)Key (b(i))110001110010(Alice)Rx Basis (B a M (i))×+×+×+×++×+×(Alice) Measure (m a(i))100101110010Channel Matching(O,N)(O,N)(N,N)(N,N)(O,O)(O,O)(O,O)(O,N)(N,O)(N,O)(N,O)(N,N)QBER Check Qubit SelectionCH1CH1CH1CH2CH2CH2Alice's Sifted Key (m a (i))010Bob's Sifted Key (m b (i))010

[0345]

[0346] In the example described above, quantum channel #1 from Alice to Bob and quantum channel #2 from Bob to Alice use different basis patterns. For quantum channel #1, basis matching occurs at indices 1, 2, 5, 6, 7, and 8, and basis matching does not occur at indices 3, 4, 9, 10, 11, and 12. On the other hand, for quantum channel #2, basis matching occurs at indices 5, 6, 7, 9, 10, and 11, and basis matching does not occur at indices 1, 2, 3, 4, 8, and 12.

[0347] Therefore, the QBER test for Quantum Channel #1 is performed on indices 1, 2, and 8, which are among the 6 indices where basis matching occurs for Quantum Channel #1 but do not occur for Quantum Channel #2. On the other hand, the QBER test for Quantum Channel #2 is performed on indices 9, 10, and 11, which are among the 6 indices where basis matching occurs for Quantum Channel #2 but do not occur for Quantum Channel #1.

[0348] If there are no issues with the QBER check of Quantum Channel #1 and Quantum Channel #2, a symmetric key can be obtained by XORing the secret value of each node with the measurement value of each node corresponding to indices 5, 6, and 7, where basis matching has been performed in both channels. Specifically, And, is. Therefore, both Alice and Bob acquire the same symmetrically shifted key '[0,1,0]'.

[0349]

[0350] FIG. 21 illustrates an example of a procedure in which a first device performs a quantum key exchange according to one embodiment of the present disclosure. FIG. 21 illustrates a method performed by one of the devices performing the quantum key exchange (e.g., Alice or Bob), and the subject of the operation is referred to as the first device.

[0351] Referring to FIG. 21, in step S2101, the first device performs an initial connection procedure. Specifically, the first device may perform synchronization by detecting a synchronization signal from the second device (e.g., a base station), receive system information, and perform a random access channel (RACH) procedure. The RACH procedure may include a four-stage RACH procedure or a two-stage RACH procedure. In the RACH procedure, the first device may transmit a RACH preamble and receive a random access response (RAR) message.

[0352] In step S2103, the first device establishes a connection. Specifically, the first device establishes a connection with the second device (e.g., an RRC connection) and may establish a connection with at least one core network entity (e.g., a NAS (non-access stratum) connection). Through this, the first device has a classic channel with the second device or has the foundational connection required to establish a classic channel thereafter.

[0353] In step S2105, the first device transmits capability information. Prior to transmitting the capability information, the first device may receive a message requesting capability information. The capability information may include information related to hardware or software capabilities related to the communication performance of the first device, and information related to procedures, functions, or features supported by the first device. In this case, according to various embodiments of the present disclosure, the capability information may include information related to quantum key distribution (e.g., whether a quantum key distribution procedure having underlying independence is supported).

[0354] In step S2107, the first device establishes a quantum channel. The quantum channel is a channel capable of transmitting quantum information (e.g., qubits) and can be established by synchronizing an optical transmitter and an optical receiver. The quantum channel can take the form of a wireless or wired connection. A quantum channel in the form of a wired connection can be implemented as a wired optical fiber-based channel. For example, the first device may receive configuration information or control information necessary for establishing the quantum channel through a classical channel from a base station, a core network, etc., and establish the quantum channel based on the received configuration information or control information.

[0355] In step S2109, the first device performs a quantum key exchange using independent bases. Here, the independent bases include a transmitting base used to transmit a quantum key stream and a measuring base for measuring a received quantum key stream. In this case, according to various embodiments of the present disclosure, the transmitting base and the receiving base may be generated independently of each other. That is, the first device may transmit a quantum key stream using the transmitting base and measure a quantum key stream received from the second device using the measuring base. And, the first device may perform a quantum key distribution procedure according to the various embodiments described above. For example, the first device may perform operations for quantum key distribution, such as Alice or Bob described with reference to FIGS. 20a and 20b.

[0356]

[0357] FIG. 22 illustrates an example of a procedure in which a second device performs a quantum key exchange according to one embodiment of the present disclosure. FIG. 22 illustrates a method performed by one of the devices performing the quantum key exchange (e.g., Alice or Bob), and the subject of the operation is referred to as the second device.

[0358] Referring to FIG. 22, in step S2201, the second device performs an initial connection procedure. Specifically, the second device may transmit a synchronization signal, transmit system information, and perform a RACH procedure. The RACH procedure may include a 4-step RACH procedure or a 2-step RACH procedure. In the RACH procedure, the second device may receive a RACH preamble from the first device and transmit a RAR message.

[0359] In step S2203, the second device establishes a connection. Specifically, the second device may establish a connection with the first device (e.g., an RRC connection). Through this, the second device has a classic channel with the first device or has the foundational connection required to establish a classic channel thereafter.

[0360] In step S2205, the second device receives capability information. Prior to transmitting the capability information, the second device may transmit a message requesting capability information to the first device. The capability information may include information related to hardware or software capabilities related to the communication performance of the first device, and information related to procedures, functions, or features supported by the first device. In this case, according to various embodiments of the present disclosure, the capability information may include information related to quantum key distribution (e.g., whether a quantum key distribution procedure having underlying independence is supported).

[0361] In step S2207, the second device establishes a quantum channel. The quantum channel is a channel capable of transmitting quantum information (e.g., qubits) and can be established by synchronizing an optical transmitter and an optical receiver. The quantum channel can be in the form of a wireless or wired connection. A quantum channel in the form of a wired connection can be implemented as a wired optical fiber-based channel. For example, the second device can transmit configuration information or control information necessary for establishing the quantum channel through a classical channel and establish the quantum channel based on the configuration information or control information.

[0362] In step S2209, the second device performs a quantum key exchange using independent bases. Here, the independent bases include a transmitting base used to transmit a quantum key stream and a measuring base for measuring a received quantum key stream. In this case, according to various embodiments of the present disclosure, the transmitting base and the receiving base may be generated independently of each other. That is, the first device may transmit a quantum key stream using the transmitting base and measure a quantum key stream received from the second device using the measuring base. And, the first device may perform a quantum key distribution procedure according to the various embodiments described above. For example, the first device may perform operations for quantum key distribution, such as Alice or Bob described with reference to FIGS. 20a and 20b.

[0363]

[0364] In the procedure described with reference to FIGS. 21 and 22, the quantum key distribution procedure may be performed by a device that performed the initial access procedure. However, FIGS. 21 and 22 are examples of cases where a terminal or base station performs quantum key distribution, and other devices other than a terminal or base station (e.g., a core network node) may also perform quantum key distribution according to an embodiment of the present disclosure.

[0365]

[0366] A bidirectional QKE having basis independence according to various embodiments of the present disclosure is performed as a logical encoding rather than a quantum encoding by performing the operation of encoding a secret key into received relative information to obtain a symmetric key when generating a shifted key. Accordingly, the number of quantum gate operations is reduced compared to conventional methods, and errors caused by quantum gates can be reduced.

[0367] In addition, a bidirectional QKE having basis independence according to various embodiments of the present disclosure can solve the problem of protocol delay or shifted key rate loss caused by conventional bidirectional QBER checks by setting a qubit selection rule for QBER checks for two quantum channels.

[0368] In addition, in the case of a bidirectional QKE having basis independence according to various embodiments of the present disclosure, in order for an attacker to steal key information, both the basis of independent quantum channel #1 and the basis of quantum channel #2 must be matched. Therefore, the probability of leakage by an attacker can be reduced to 1 / 2.

[0369] Bidirectional QKE having underlying independence according to various embodiments of the present disclosure obtains a final symmetric key by performing the same operation at the same time on two nodes. Therefore, when equivalent network nodes execute the protocol, they can share the key through completely identical operations. Consequently, the protocol can be executed without establishing priority or dependency relationships between the two nodes.

[0370] Bidirectional QKE having basis independence according to various embodiments of the present disclosure can be applied as a key distribution method that provides quantum property-based physical security to all methods where the existing classical Diffie-Hellman (DH) key exchange is applied. For example, bidirectional QKE having basis independence according to various embodiments of the present disclosure can be applied to IKEv1 or IKEv2 DH methods operating for key distribution at the Network Layer, or to DH methods for session key distribution at the Transport Layer.

[0371] A bidirectional QKE procedure having basis independence according to various embodiments of the present disclosure can be used as a quantum key distribution method to counter quantum algorithm threats of classical DH key exchange. Furthermore, a bidirectional QKE procedure having basis independence according to various embodiments of the present disclosure can reduce quantum gate errors of the classical bidirectional QKE method and can solve the problems of protocol delay or key rate loss of the classical bidirectional QKE method. Moreover, a bidirectional QKE procedure having basis independence according to various embodiments of the present disclosure can provide higher security than the classical bidirectional QKE method.

[0372]

[0373] Hereinafter, examples of wireless device applications to which various embodiments of the present disclosure are applied will be described.

[0374] FIG. 23 illustrates an example of a wireless device applicable to the present disclosure. The wireless device may be implemented in various forms depending on the use—example / service (see FIG. 1).

[0375] Referring to FIG. 23, the wireless device (200) corresponds to the wireless device (200) of FIG. 2 and may be composed of various elements, components, units / parts, and / or modules. For example, the wireless device (200) may include a communication unit (210), a control unit (220), a memory unit (230), and additional elements (240). The communication unit may include a communication circuit (212) and transceiver(s) (214). For example, the communication circuit (212) may include one or more processors (202) and / or one or more memories (204) of FIG. 2. For example, the transceiver(s) (214) may include one or more transceivers (206) and / or one or more antennas (208) of FIG. 2. The control unit (220) is electrically connected to the communication unit (210), the memory unit (230), and additional elements (240) and controls the overall operation of the wireless device. For example, the control unit (220) can control the electrical / mechanical operation of the wireless device based on a program / code / command / information stored in the memory unit (230). Additionally, the control unit (220) can transmit information stored in the memory unit (230) to an external entity (e.g., another communication device) via a wireless / wired interface through the communication unit (210), or store information received from an external entity (e.g., another communication device) via a wireless / wired interface through the communication unit (210) in the memory unit (230).

[0376] The additional element (240) may be configured in various ways depending on the type of wireless device. For example, the additional element (240) may include at least one of a power unit / battery, an input / output unit (I / O unit), a driving unit, and a computing unit. Although not limited thereto, the wireless device may be implemented in the form of a robot (Fig. 1, 100a), a vehicle (Fig. 1, 100b-1, 100b-2), an XR device (Fig. 1, 100c), a portable device (Fig. 1, 100d), a home appliance (Fig. 1, 100e), an IoT device (Fig. 1, 100f), a digital broadcasting terminal, a holographic device, a public safety device, an MTC device, a medical device, a fintech device (or financial device), a security device, a climate / environment device, an AI server / device (Fig. 1, 400), a base station (Fig. 1, 200), a network node, etc. Depending on the use—e.g., service—the wireless device may be movable or used in a fixed location.

[0377] In FIG. 23, various elements, components, units / parts, and / or modules within the wireless device (200) may be entirely interconnected via a wired interface, or at least partially connected via a communication unit (210). For example, within the wireless device (200), the control unit (220) and the communication unit (210) may be connected via a wire, and the control unit (220) and the first unit (e.g., 230, 240) may be connected wirelessly via the communication unit (210). Additionally, each element, component, unit / part, and / or module within the wireless device (200) may include one or more additional elements. For example, the control unit (220) may be composed of one or more sets of processors. For example, the control unit (220) may be composed of a set of a communication control processor, an application processor, an Electronic Control Unit (ECU), a graphics processing processor, a memory control processor, etc. As another example, the memory unit (130) may be composed of RAM (Random Access Memory), DRAM (Dynamic RAM), ROM (Read Only Memory), flash memory, volatile memory, non-volatile memory and / or a combination thereof.

[0378] Hereinafter, an implementation example of FIG. 23 will be described in more detail with reference to the drawings.

[0379] FIG. 24 illustrates an example of a portable device applicable to the present disclosure. A portable device may include a smartphone, a smartpad, a wearable device (e.g., a smartwatch, smart glasses), or a portable computer (e.g., a laptop). A portable device may be referred to as a Mobile Station (MS), a User Terminal (UT), a Mobile Subscriber Station (MSS), a Subscriber Station (SS), an Advanced Mobile Station (AMS), or a Wireless Terminal (WT).

[0380] Referring to FIG. 24, the portable device (200) may include an antenna unit (208), a communication unit (210), a control unit (220), a memory unit (230), a power supply unit (240a), an interface unit (240b), and an input / output unit (240c). The antenna unit (208) may be configured as part of the communication unit (210). Blocks 210 to 230 / 240a to 240c of FIG. 24 correspond to blocks 210 to 230 / 240 of FIG. 23, respectively.

[0381] The communication unit (210) can transmit and receive signals (e.g., data, control signals, etc.) with other wireless devices and base stations. The control unit (220) can control the components of the portable device (200) to perform various operations. The control unit (220) may include an AP (Application Processor). The memory unit (230) can store data / parameters / programs / code / commands required for the operation of the portable device (200). Additionally, the memory unit (230) can store input / output data / information, etc. The power supply unit (240a) supplies power to the portable device (200) and may include wired / wireless charging circuits, batteries, etc. The interface unit (240b) can support the connection between the portable device (200) and other external devices. The interface unit (240b) may include various ports (e.g., audio input / output ports, video input / output ports) for connection with external devices. The input / output unit (240c) can receive or output video information / signals, audio information / signals, data, and / or information input by a user. The input / output unit (240c) may include a camera, a microphone, a user input unit, a display unit (240d), a speaker and / or a haptic module, etc.

[0382] For example, in the case of data communication, the input / output unit (240c) acquires information / signals (e.g., touch, text, voice, image, video) input by the user, and the acquired information / signals can be stored in the memory unit (230). The communication unit (210) converts the information / signals stored in the memory into wireless signals and can directly transmit the converted wireless signals to another wireless device or to a base station. Additionally, the communication unit (210) can receive wireless signals from another wireless device or base station and then restore the received wireless signals to their original information / signals. The restored information / signals are stored in the memory unit (230) and then can be output in various forms (e.g., text, voice, image, video, haptic) through the input / output unit (240c).

[0383] FIG. 25 illustrates an example of a vehicle or autonomous vehicle applicable to the present disclosure. The vehicle or autonomous vehicle may be implemented as a mobile robot, a vehicle, a train, an aerial vehicle (AV), a ship, etc.

[0384] Referring to FIG. 25, a vehicle or autonomous vehicle (200-1) may include an antenna unit (208-1), a communication unit (210-1), a control unit (220-1), a driving unit (240a-1), a power supply unit (240b-1), a sensor unit (240c-1), and an autonomous driving unit (240d-1). The antenna unit (208-1) may be configured as part of the communication unit (210-1). Blocks 210-1 / 230-1 / 240a-1 to 240d-1 of FIG. 25 correspond to blocks 210 / 230 / 240 of FIG. 23, respectively.

[0385] The communication unit (210-1) can transmit and receive signals (e.g., data, control signals, etc.) with external devices such as other vehicles, base stations (e.g., base stations, roadside base stations (Road Side Unit), etc.), and servers. The control unit (220-1) can perform various operations by controlling elements of the vehicle or autonomous vehicle (200-1). The control unit (220-1) may include an Electronic Control Unit (ECU). The driving unit (240a-1) can drive the vehicle or autonomous vehicle (200-1) on the ground. The driving unit (240a-1) may include an engine, motor, power train, wheels, brakes, steering device, etc. The power supply unit (240b-1) supplies power to the vehicle or autonomous vehicle (200-1) and may include wired / wireless charging circuits, batteries, etc. The sensor unit (240c-1) can obtain vehicle status, surrounding environment information, user information, etc. The sensor unit (240c-1) may include an IMU (inertial measurement unit) sensor, a collision sensor, a wheel sensor, a speed sensor, an inclination sensor, a weight detection sensor, a heading sensor, a position module, a vehicle forward / reverse sensor, a battery sensor, a fuel sensor, a tire sensor, a steering sensor, a temperature sensor, a humidity sensor, an ultrasonic sensor, an illuminance sensor, a pedal position sensor, etc. The autonomous driving unit (240d-1) may implement technologies such as maintaining the driving lane, technologies for automatically adjusting speed such as adaptive cruise control, technologies for automatically driving along a predetermined path, and technologies for automatically setting a path and driving when a destination is set.

[0386] For example, the communication unit (210-1) can receive map data, traffic information data, etc. from an external server. The autonomous driving unit (240d-1) can generate an autonomous driving path and a driving plan based on the acquired data. The control unit (220-1) can control the drive unit (240a-1) so that the vehicle or the autonomous vehicle (200-1) moves along the autonomous driving path according to the driving plan (e.g., speed / direction control). During autonomous driving, the communication unit (210-1) can acquire the latest traffic information data from an external server non-periodically and can acquire surrounding traffic information data from surrounding vehicles. Additionally, during autonomous driving, the sensor unit (240c-1) can acquire vehicle status and surrounding environment information. The autonomous driving unit (240d-1) can update the autonomous driving path and the driving plan based on the newly acquired data / information. The communication unit (210-1) can transmit information regarding the vehicle location, autonomous driving path, driving plan, etc. to an external server. An external server can predict traffic information data in advance using AI technology, etc., based on information collected from vehicles or autonomous vehicles, and can provide the predicted traffic information data to vehicles or autonomous vehicles. If the device (220-2) is an autonomous vehicle, it can perform the same procedure as the vehicle or autonomous vehicle (200-1). In addition, if the device (220-2) is a base station or a roadside base station, the device (220-2) can transmit data and control signals to the vehicle or autonomous vehicle (200-1) through the communication unit (210-2).

[0387] FIG. 26 illustrates an example of a vehicle applicable to the present disclosure. The vehicle may be implemented as a means of transport, a train, an aircraft, a ship, etc. Referring to FIG. 26, the vehicle (200) may include a communication unit (210), a control unit (220), a memory unit (230), an input / output unit (240a), and a position measurement unit (240b). Here, blocks 210 to 230 / 240a to 240b correspond to blocks 210 to 230 / 240 of FIG. 23, respectively.

[0388] The communication unit (210) can transmit and receive signals (e.g., data, control signals, etc.) with other vehicles or external devices such as base stations. The control unit (220) can control the components of the vehicle (200) to perform various operations. The memory unit (230) can store data / parameters / programs / codes / commands that support various functions of the vehicle (100). The input / output unit (240a) can output AR / VR objects based on information within the memory unit (230). The input / output unit (240a) may include a HUD. The position measurement unit (240b) can acquire position information of the vehicle (200). The position information may include absolute position information of the vehicle (200), position information within the driving line, acceleration information, position information relative to surrounding vehicles, etc. The position measurement unit (240b) may include GPS and various sensors.

[0389] For example, the communication unit (210) of the vehicle (200) can receive map information, traffic information, etc. from an external server and store it in the memory unit (230). The location measurement unit (240b) can acquire vehicle location information through GPS and various sensors and store it in the memory unit (230). The control unit (220) creates a virtual object based on map information, traffic information, and vehicle location information, etc., and the input / output unit (240a) can display the created virtual object on the glass window inside the vehicle (240a-1, 240a-2). In addition, the control unit (220) can determine whether the vehicle (200) is operating normally within the driving line based on the vehicle location information. If the vehicle (200) deviates abnormally from the driving line, the control unit (220) can display a warning on the glass window inside the vehicle through the input / output unit (240a). Additionally, the control unit (220) can broadcast a warning message regarding a driving abnormality to surrounding vehicles through the communication unit (210). Depending on the situation, the control unit (220) can transmit the vehicle's location information and information regarding the driving / vehicle abnormality to relevant authorities through the communication unit (210).

[0390] FIG. 27 illustrates an example of an XR device applicable to the present disclosure. The XR device may be implemented as an HMD, a Head-Up Display (HUD) equipped in a vehicle, a television, a smartphone, a computer, a wearable device, a home appliance, digital signage, a vehicle, a robot, etc.

[0391] Referring to FIG. 27, the XR device (200a) may include a communication unit (210), a control unit (220), a memory unit (230), an input / output unit (240a), a sensor unit (240b), and a power supply unit (240c). Here, blocks 210 to 230 / 240a to 240c of FIG. 27 correspond to blocks 210 to 230 / 240 of FIG. 23, respectively.

[0392] The communication unit (210) can transmit and receive signals (e.g., media data, control signals, etc.) with external devices such as other wireless devices, mobile devices, or media servers. The media data may include video, images, sound, etc. The control unit (220) can control the components of the XR device (200a) to perform various operations. For example, the control unit (220) may be configured to control and / or perform procedures such as video / image acquisition, (video / image) encoding, metadata generation, and processing. The memory unit (230) may store data / parameters / programs / code / commands required for driving the XR device (200a) or creating an XR object. The input / output unit (240a) acquires control information, data, etc. from the outside and can output the created XR object. The input / output unit (240a) may include a camera, microphone, user input unit, display unit, speaker and / or haptic module, etc. The sensor unit (240b) can obtain XR device status, surrounding environment information, user information, etc. The sensor unit (240b) may include a proximity sensor, an illuminance sensor, an accelerometer, a magnetic sensor, a gyroscope, an inertial sensor, an RGB sensor, an IR sensor, a fingerprint recognition sensor, an ultrasonic sensor, a light sensor, a microphone and / or radar, etc. The power supply unit (240c) supplies power to the XR device (200a) and may include a wired / wireless charging circuit, a battery, etc.

[0393] For example, the memory unit (230) of the XR device (200a) may contain information (e.g., data, etc.) necessary for creating an XR object (e.g., AR / VR / MR object). The input / output unit (240a) may receive a command to operate the XR device (200a) from the user, and the control unit (220) may operate the XR device (200a) according to the user's operation command. For example, if the user intends to watch movies, news, etc. through the XR device (200a), the control unit (220) may transmit content request information to another device (e.g., mobile device (200b)) or a media server through the communication unit (230). The communication unit (230) may download / stream content such as movies, news, etc. from another device (e.g., mobile device (200b)) or a media server to the memory unit (230). The control unit (220) controls and / or performs procedures such as video / image acquisition, (video / image) encoding, and metadata generation / processing for the content, and can generate / output an XR object based on information about the surrounding space or real object acquired through the input / output unit (240a) / sensor unit (240b).

[0394] Additionally, the XR device (200a) is wirelessly connected to the mobile device (200b) through the communication unit (210), and the operation of the XR device (200a) can be controlled by the mobile device (200b). For example, the mobile device (200b) can act as a controller for the XR device (200a). To this end, the XR device (200a) can acquire three-dimensional position information of the mobile device (200b), and then generate and output an XR object corresponding to the mobile device (200b).

[0395] FIG. 28 illustrates an example of a robot applicable to the present disclosure. Robots may be classified into industrial, medical, domestic, military, etc., depending on the purpose or field of use.

[0396] Referring to FIG. 28, the robot (200) may include a communication unit (210), a control unit (220), a memory unit (230), an input / output unit (240a), a sensor unit (240b), and a driving unit (240c). Here, blocks 210 to 230 / 240a to 240c of FIG. 28 correspond to blocks 210 to 230 / 240 of FIG. 23, respectively.

[0397] The communication unit (210) can transmit and receive signals (e.g., driving information, control signals, etc.) with external devices such as other wireless devices, other robots, or control servers. The control unit (220) can control the components of the robot (200) to perform various operations. The memory unit (230) can store data / parameters / programs / codes / commands that support various functions of the robot (200). The input / output unit (240a) can acquire information from outside the robot (200) and output information to outside the robot (200). The input / output unit (240a) may include a camera, microphone, user input unit, display unit, speaker and / or haptic module, etc. The sensor unit (240b) can obtain internal information of the robot (200), surrounding environment information, user information, etc. The sensor unit (240b) may include a proximity sensor, an illuminance sensor, an accelerometer, a magnetic sensor, a gyroscope, an inertial sensor, an IR sensor, a fingerprint recognition sensor, an ultrasonic sensor, a light sensor, a microphone, a radar, etc. The driving unit (240c) may perform various physical movements, such as moving robot joints. Additionally, the driving unit (240c) may enable the robot (200) to travel on the ground or fly in the air. The driving unit (240c) may include an actuator, a motor, a wheel, a brake, a propeller, etc.

[0398] FIG. 29 illustrates an example of an AI device applicable to the present disclosure.

[0399] AI devices can be implemented as stationary devices or mobile devices, such as TVs, projectors, smartphones, PCs, laptops, digital broadcasting terminals, tablet PCs, wearable devices, set-top boxes (STBs), radios, washing machines, refrigerators, digital signage, robots, vehicles, etc.

[0400] Referring to FIG. 29, the AI ​​device (200) may include a communication unit (210), a control unit (220), a memory unit (230), an input / output unit (240a / 240b), a learning processor unit (240c), and a sensor unit (240d). Blocks 210 to 230 / 240a to 240d of FIG. 29 correspond to blocks 210 to 230 / 140 of FIG. 23, respectively.

[0401] The communication unit (210) can transmit and receive wired and wireless signals (e.g., sensor information, user input, learning model, control signal, etc.) with external devices such as other AI devices (e.g., 100a to 100f, 120 in FIG. 1) or AI servers (e.g., 100g in FIG. 1) using wired and wireless communication technology. To this end, the communication unit (210) can transmit information within the memory unit (230) to an external device or transmit signals received from an external device to the memory unit (230).

[0402] The control unit (220) can determine at least one executable operation of the AI ​​device (200) based on information determined or generated using a data analysis algorithm or a machine learning algorithm. The control unit (220) can perform the determined operation by controlling the components of the AI ​​device (200). For example, the control unit (220) can request, search, receive, or utilize data from the learning processor unit (240c) or the memory unit (230), and can control the components of the AI ​​device (200) to execute a predicted operation or an operation determined to be desirable among at least one executable operation. Additionally, the control unit (220) can collect historical information, including the operation content of the AI ​​device (200) or user feedback regarding the operation, and store it in the memory unit (230) or the learning processor unit (240c), or transmit it to an external device such as an AI server (Fig. 1, 100g). The collected historical information can be used to update the learning model.

[0403] The memory unit (230) can store data that supports various functions of the AI ​​device (200). For example, the memory unit (230) can store data obtained from the input unit (240a), data obtained from the communication unit (210), output data from the learning processor unit (240c), and data obtained from the sensing unit (140). Additionally, the memory unit (230) can store control information and / or software code required for the operation / execution of the control unit (220).

[0404] The input unit (240a) can acquire various types of data from outside the AI ​​device (200). For example, the input unit (220) can acquire training data for model training and input data to which the training model is applied. The input unit (240a) may include a camera, a microphone and / or a user input unit, etc. The output unit (240b) can generate output related to visual, auditory, or tactile senses, etc. The output unit (240b) may include a display unit, a speaker and / or a haptic module, etc. The sensing unit (140d) can obtain at least one of internal information of the AI ​​device (200), surrounding environment information of the AI ​​device (200), and user information using various sensors. The sensing unit (140d) may include a proximity sensor, an illuminance sensor, an accelerometer, a magnetic sensor, a gyroscope, an inertial sensor, an RGB sensor, an IR sensor, a fingerprint recognition sensor, an ultrasonic sensor, a light sensor, a microphone and / or radar, etc.

[0405] The learning processor unit (240c) can train a model composed of an artificial neural network using training data. The learning processor unit (240c) can perform AI processing together with the learning processor unit of the AI ​​server (Fig. 1, 100g). The learning processor unit (240c) can process information received from an external device through the communication unit (210) and / or information stored in the memory unit (230). Additionally, the output value of the learning processor unit (240c) can be transmitted to an external device through the communication unit (210) and / or stored in the memory unit (230).

[0406]

[0407] FIG. 30 illustrates an example of a quantum communication device applicable to the present disclosure. The quantum communication device can be applied to various devices and can be operated in combination (or merged) with other wired and / or wireless communication devices that are not quantum communication devices. Information in quantum communication may be a concept that includes both bit information, which is the basic unit of classical information, and qubit information, which is the basic unit of quantum information.

[0408] The channel encoder (250) can encode the classical bit to be transmitted into a coded bit. The channel encoder (250) can improve the reliability of the classical bit. The quantum encoder (260) converts the coded bit into a qubit basis (or computation basis). Here, the qubit basis is logical information about the quantum state and can be formed based on a physical quantum basis. For example, as quantum bases at the transmitting and receiving ends, horizontal polarization and vertical polarization can be agreed to correspond to the qubit bases |0〉 and |1〉, respectively.

[0409] Through the channel encoder (250) and the quantum encoder (260), classical information bits 0 or 1 can be converted into qubit bases |0〉 or |1〉. The qubit bases generated at the transmitting end can be transmitted to the receiving end through the quantum channel.

[0410] The quantum decoder (270) at the receiving end can perform measurements based on a pre-agreed quantum basis to decode the qubit basis transmitted to the receiving end into a coded bit. If multiple qubit bases determine the qubit state, a qubit coded deterministically or probabilistically can be obtained depending on the measured qubit basis.

[0411] The channel decoder (280) can decode the coded bits back into classical bits and obtain the information bits sent by the transmitting end.

[0412] The procedures related to the channel encoder (250) and channel decoder (280), indicated by dotted lines in FIG. 30, may be omitted. When the channel encoder (250) and channel decoder (280) are omitted, the qubit state from the quantum process at the transmitting end can be transmitted to the receiving end through a quantum channel. The received qubit state can be used for various purposes by the quantum processor. For example, to transmit the qubit state generated by the quantum processor, a quantum direct communication method in which the qubit state is converted into a photon and transmitted may be used, or a method of performing quantum teleportation based on an entanglement source shared in advance between the transmitting and receiving ends may be used. Here, quantum direct communication refers to a communication method in which classical message information to be transmitted is immediately and securely shared through a quantum channel, and quantum teleportation refers to a communication method in which the quantum information itself is shared through a quantum entanglement channel.

[0413]

[0414] The proposed methods described above may be implemented independently, but they may also be implemented in the form of a combination (or merger) of some of the proposed methods. Rules may be defined so that the base station informs the terminal of the application status of the proposed methods (or information regarding the rules of the proposed methods) through a predefined signal (e.g., a physical layer signal or an upper layer signal).

[0415] The present disclosure may be embodied in other specific forms without departing from the technical ideas and essential features described herein. Accordingly, the above detailed description should not be interpreted restrictively in all respects and should be considered illustrative. The scope of the present disclosure shall be determined by a reasonable interpretation of the appended claims, and all modifications within the equivalent scope of the present disclosure are included within the scope of the present disclosure. Furthermore, embodiments may be constructed by combining claims that are not explicitly related in the claims, or new claims may be included by amendments made after filing.

[0416] One embodiment can be applied to various wireless access systems. Examples of various wireless access systems include the 3GPP (3rd Generation Partnership Project) or 3GPP2 system.

[0417] One embodiment can be applied not only to the various wireless access systems mentioned above, but also to all technical fields utilizing the various wireless access systems. Furthermore, the proposed method can be applied to mmWave and THz communication systems utilizing the ultra-high frequency band.

[0418] Additionally, some embodiments may be applied to various applications such as autonomous vehicles and drones.

Claims

1. Regarding the method, A step of performing a connection procedure with a second device by means of a first device; A step of establishing a connection with the second device; A step of transmitting capability information to the second device; A step of establishing at least one quantum channel with the second device; and The method includes the step of performing a quantum key exchange using at least one quantum channel, The above quantum key exchange is a method performed using different transmit basis and measurement basis.

2. In Claim 1, The step of performing the above quantum key exchange is, A step of transmitting to the second device an initial quantum key stream, which is a quantum state generated based on a secret key sequence and a first transmission basis; A step of performing basis compensation based on a first measurement basis for a quantum state received from the second device; A step of receiving information related to a second transmitting base and a second measuring base of the second device through a classical channel from the second device; A step of selecting at least one test qubit for QBER (quantum bit error rate) inspection based on the first transmission basis and the second measurement basis; A step of transmitting information related to at least one inspection qubit to the second device; A method comprising the step of determining a shift key based on information related to the result of the QBER inspection received from the second device.

3. In Claim 2, The above initial quantum key stream is generated by applying a unitary operation by a secret key and a unitary operation by the first transmission basis to the initial qubit state.

4. In Claim 2, The first transmission basis above includes a plurality of randomly selected basis values, and The first measurement basis above includes a plurality of randomly selected basis values, and The above first transmission basis and the above first measurement basis are determined independently of each other.

5. In Claim 2, The step of selecting at least one inspection qubit is, A step of generating basis matching information indicating whether there is a matching for each basis value of the first transmitting basis and the second measuring basis, and second basis matching information indicating whether there is a matching for each basis value of the second transmitting basis and the first measuring basis; A method comprising the step of selecting at least one inspection qubit based on the first basis matching information or the second basis matching information.

6. In Claim 5, A method comprising at least one inspection qubit, wherein the at least one qubit is indicated as matching by the first basis matching information and indicated as non-matching by the second basis matching information.

7. In Claim 2, The above at least one inspection qubit is, A method comprising at least one qubit having an index in which basis matching is performed in a quantum channel transmitted from the first device and basis matching is not performed in a quantum channel transmitted from the second device.

8. In Claim 2, Information related to the above-mentioned at least one inspection qubit includes the index and value of at least one qubit included in the above-mentioned at least one inspection qubit.

9. In Claim 8, The above QBER inspection is performed based on a comparison of the value of the at least one inspection qubit transmitted from the first device and the measurement value by the second device for at least one qubit indicated by the index of the at least one inspection qubit transmitted from the first device.

10. In Claim 9, Information related to the result of the above QBER inspection is a method for indicating whether the number of qubits in which the value transmitted from the first device and the value measured from the second device do not match for at least one qubit exceeds a threshold.

11. In Claim 2, The step of determining the above shift key is, A method comprising the step of generating the shift key when information related to the result of the QBER check received from the second device indicates that, for at least one qubit, the number of qubits in which the value transmitted from the first device and the value measured from the second device do not match is less than or equal to a threshold, and the result of the QBER check performed by the first device indicates that, for at least one qubit selected by the second device, the number of qubits in which the value transmitted from the second device and the value measured from the first device do not match is less than or equal to the threshold.

12. Regarding the method, A step of establishing at least one quantum channel with a second device by means of a first device; and The method includes the step of performing a quantum key exchange using at least one quantum channel, The above quantum key exchange is a method performed using different transmit basis and measurement basis.

13. In the first device, Transmitter / receiver; and It includes a processor coupled to the above-mentioned transmitter and receiver, The above processor is, Perform the connection procedure with the second device, Establish a connection with the above-mentioned second device, and Transmitting capability information to the above-mentioned second device, and Establish at least one quantum channel with the above-mentioned second device, and It is configured to perform quantum key exchange using at least one quantum channel, and The above quantum key exchange is performed using a first device with different transmit basis and measurement basis.

14. In the second device, Transmitter / receiver; and It includes a processor coupled to the above-mentioned transmitter and receiver, The above processor is, By the first device, at least one quantum channel is established with the second device, and It is configured to perform quantum key exchange using at least one quantum channel, and The above quantum key exchange is performed using a second device with different transmit basis and measurement basis.

15. In the first device, At least one processor; It includes at least one memory connected to the at least one processor and storing instructions that cause a terminal to perform operations as executed by the at least one processor, The above operations are, Step of performing a connection procedure with the second device; A step of establishing a connection with the second device; A step of transmitting capability information to the second device; A step of establishing at least one quantum channel with the second device; and The method includes the step of performing a quantum key exchange using at least one quantum channel, The above quantum key exchange is performed using a first device with different transmit basis and measurement basis.

16. In a non-transitory computer-readable medium storing at least one program instruction, The above at least one program instruction causes the first device to perform operations as it is executed by at least one processor, and The above operations are, Step of performing a connection procedure with the second device; A step of establishing a connection with the second device; A step of transmitting capability information to the second device; A step of establishing at least one quantum channel with the second device; and The method includes the step of performing a quantum key exchange using at least one quantum channel, The above quantum key exchange is performed on a computer-readable medium using different transmit basis and measurement basis.

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