Method and apparatus for supporting security mechanisms having different security levels in mobile communication system

Abstract

The present disclosure relates to a method performed in a 5G or 6G communication system for supporting a higher data transmission rate, the method comprising the steps of: receiving, from a user equipment (UE), first information capable of specifying the UE; and transmitting, to a second network entity, second information related to an algorithm supported by the UE and a first network entity on the basis of the first information capable of specifying the UE, wherein the second information includes information notifying that the algorithm supported by the UE and the first network entity includes an algorithm having a high security level.

Description

Method and device for supporting security mechanisms of different security levels in a mobile communication system

[0001] The present disclosure relates to a wireless communication system, and more specifically, to a method and device for linking entities of different security levels when entities constituting a terminal and a network have different security levels in a process of authenticating each other and forming a shared key to be used for secure communication in a wireless communication system.

[0002] 5G mobile communication technology defines a wide frequency band to enable fast transmission speeds and new services, and can be implemented not only in the sub-6GHz frequency band such as 3.5 gigahertz (3.5GHz), but also in the ultra-high frequency band called millimeter wave (mmWave) such as 28GHz and 39GHz ('Above 6GHz'). In addition, for 6G mobile communication technology, which is called the system after 5G communication (Beyond 5G), implementation in the terahertz (THz) band (for example, 3 THz band at 95GHz) is being considered to achieve a transmission speed that is 50 times faster than 5G mobile communication technology and an ultra-low latency time that is reduced to one-tenth.

[0003] In the early stages of 5G mobile communication technology, the goal is to support services and satisfy performance requirements for enhanced Mobile Broadband (eMBB), Ultra-Reliable Low-Latency Communications (URLLC), and massive Machine-Type Communications (mMTC). These include beamforming and massive MIMO to mitigate path loss of radio waves in ultra-high frequency bands and increase the transmission distance of radio waves, support for various numerologies (such as operation of multiple subcarrier intervals) and dynamic operation of slot formats for efficient use of ultra-high frequency resources, initial access technology to support multi-beam transmission and wideband, definition and operation of BWP (Bidth Part), new channel coding methods such as LDPC (Low Density Parity Check) codes for large-capacity data transmission and Polar Code for reliable transmission of control information, and L2 pre-processing (L2). Standardization has been made for network slicing, which provides dedicated networks specialized for specific services, and pre-processing.

[0004] Currently, discussions are underway to improve and enhance the initial 5G mobile communication technology in consideration of the services that 5G mobile communication technology was intended to support, and physical layer standardization is in progress for technologies such as V2X (Vehicle-to-Everything) to help autonomous vehicles make driving decisions and increase user convenience based on their own location and status information transmitted by vehicles, NR-U (New Radio Unlicensed) for the purpose of system operation that complies with various regulatory requirements in unlicensed bands, NR terminal low power consumption technology (UE Power Saving), Non-Terrestrial Network (NTN), which is direct terminal-satellite communication to secure coverage in areas where communication with terrestrial networks is impossible, and Positioning.

[0005] In addition, standardization of wireless interface architecture / protocols is in progress for technologies such as intelligent factories (Industrial Internet of Things, IIoT) to support new services through linkage and convergence with other industries, Integrated Access and Backhaul (IAB) that provides nodes for expanding network service areas by integrating wireless backhaul links and access links, Mobility Enhancement technology including Conditional Handover and Dual Active Protocol Stack (DAPS) handover, and 2-step random access (2-step RACH for NR) that simplifies random access procedures. Standardization is also in progress for system architecture / services such as 5G baseline architecture (e.g., Service-based Architecture, Service-based Interface) for grafting Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technologies, and Mobile Edge Computing (MEC) that provides services based on the location of the terminal.

[0006] Once these 5G mobile communication systems are commercialized, an explosive increase in connected devices will be connected to the communication network, necessitating enhanced functionality and performance of 5G mobile communication systems and integrated operation of these connected devices. To this end, new research will be conducted on improving 5G performance and reducing complexity, supporting AI services, supporting metaverse services, and drone communications by utilizing eXtended Reality (XR), Artificial Intelligence (AI), and Machine Learning (ML) to efficiently support Augmented Reality (AR), Virtual Reality (VR), and Mixed Reality (MR).

[0007] In addition, the development of these 5G mobile communication systems includes new waveforms to ensure coverage in the terahertz band of 6G mobile communication technology, multi-antenna transmission technologies such as Full Dimensional MIMO (FD-MIMO), Array Antenna, and Large Scale Antenna, metamaterial-based lenses and antennas to improve the coverage of terahertz band signals, high-dimensional spatial multiplexing technology using Orbital Angular Momentum (OAM), Reconfigurable Intelligent Surface (RIS) technology, as well as full duplex technology to improve the frequency efficiency and system network of 6G mobile communication technology, satellite, AI (Artificial Intelligence) from the design stage and AI-based communication technology that realizes system optimization by internalizing end-to-end AI support functions, and ultra-high-performance communication and computing resources to provide services with complexity that exceeds the limits of terminal computing capabilities. It can serve as a basis for the development of next-generation distributed computing technologies that can be realized by utilizing them.

[0008] Based on the above discussion, the purpose of this disclosure is to address the following issues. In a wireless communication system, when a terminal and a network authenticate each other and establish a shared key to be used for future secure communication, the entities constituting the terminal and the network may have different security levels. Currently used methods are designed without considering the situation where these entities have different security levels, which can lead to problems. Therefore, the present disclosure aims to address the aforementioned issues.

[0009] The present invention for solving the above problems comprises a method performed by a first network entity in a wireless communication system, the method comprising: receiving, from a UE (User Equipment), first information capable of identifying the UE; and transmitting, to a second network entity, second information related to an algorithm supported by the UE and the first network entity based on the first information capable of identifying the UE, wherein the second information is information notifying that the algorithm supported by the UE and the first network entity includes an algorithm having a high security level.

[0010] In one embodiment, the first information is characterized in that it is associated with an encryption algorithm supported by the UE.

[0011] In one embodiment, the method further comprises receiving third information necessary for deriving a high-security level encryption key related to authentication and shared key generation from the second network entity.

[0012] In one embodiment, when the third information is received, the method further includes a step of transmitting all or part of the third information to the UE, wherein the UE includes a subscriber identity module (SIM) and a mobile equipment (ME), and all or part of the third information is transmitted from the ME to the SIM.

[0013] In addition, in another embodiment of the present invention, a method performed by a second network entity in a wireless communication system includes a step of receiving, from a first network entity, second information related to an algorithm supported by the UE and the first network entity based on first information capable of specifying the UE, wherein the first information capable of specifying the UE is transmitted from the UE to the first network entity, and the second information is characterized in that it is information notifying that the algorithm supported by the UE and the first network entity includes an algorithm of a high security level.

[0014] In addition, in another embodiment of the present invention, in a wireless communication system, a first network entity includes a transceiver capable of transmitting and receiving at least one signal; and a control unit coupled to the transceiver, wherein the control unit is configured to: receive, from a UE (User Equipment), first information capable of specifying the UE, and transmit, to a second network entity, second information related to an algorithm supported by the UE and the first network entity based on the first information capable of specifying the UE, wherein the second information is information notifying that the algorithm supported by the UE and the first network entity includes an algorithm of a high security level.

[0015] In addition, in another embodiment of the present invention, in a wireless communication system, a second network entity includes a transceiver capable of transmitting and receiving at least one signal; and a control unit coupled to the transceiver, wherein the control unit is configured to receive, from a first network entity, second information related to an algorithm supported by the UE and the first network entity based on first information capable of specifying the UE, wherein the first information capable of specifying the UE is transmitted from the UE to the first network entity, and the second information is characterized in that it is information notifying that the algorithm supported by the UE and the first network entity includes an algorithm having a high security level.

[0016] Various embodiments of the present disclosure can provide a device and method capable of effectively providing a service in a wireless communication system.

[0017] The effects that can be obtained from the present disclosure are not limited to the effects mentioned in the various embodiments, and other effects that are not mentioned can be clearly understood by a person having ordinary skill in the art to which the present disclosure belongs from the description below.

[0018] FIG. 1A is a diagram illustrating a communication network including core network entities in a wireless communication system according to various embodiments of the present disclosure.

[0019] FIG. 1b is a diagram illustrating a wireless environment including a core network in a wireless communication system according to various embodiments of the present disclosure.

[0020] FIG. 2A is a diagram illustrating an example of a functional structure of a terminal according to embodiments of the present disclosure.

[0021] FIG. 2b is a diagram illustrating an example of a functional structure of a base station according to embodiments of the present disclosure.

[0022] FIG. 2c is a diagram illustrating an example of a functional structure of a core network object according to embodiments of the present disclosure.

[0023] FIG. 3 is a diagram illustrating a hierarchy of encryption keys generated by a terminal and a network for secure communication according to an embodiment of the present disclosure.

[0024] FIG. 4 is a diagram illustrating an authentication process of a terminal and a network and a shared key formation process for secure communication according to one embodiment of the present disclosure.

[0025] FIG. 5 is a diagram illustrating an authentication process and a shared key formation process for secure communication between a terminal and a network that may have different security levels according to an embodiment of the present disclosure.

[0026] FIG. 6 is a diagram illustrating an authentication process and a shared key formation process for secure communication between a terminal and a network that may have different security levels according to another embodiment of the present disclosure.

[0027] The terms used in this disclosure are used only to describe specific embodiments and may not be intended to limit the scope of other embodiments. The singular expression may include plural expressions unless the context clearly indicates otherwise. Terms used herein, including technical or scientific terms, may have the same meaning as commonly understood by those of ordinary skill in the art described in this disclosure. Terms defined in general dictionaries among the terms used in this disclosure may be interpreted as having the same or similar meaning in the context of the relevant technology, and shall not be interpreted in an idealized or overly formal sense unless explicitly defined in this disclosure. In some cases, even if a term is defined in this disclosure, it cannot be interpreted to exclude embodiments of the present disclosure.

[0028] The various embodiments of the present disclosure described below illustrate a hardware-based approach as an example. However, since the various embodiments of the present disclosure include techniques utilizing both hardware and software, the various embodiments of the present disclosure do not exclude a software-based approach.

[0029] 3GPP, responsible for cellular mobile communications standards, is standardizing a new core network architecture, dubbed 5G core (5GC), to facilitate the evolution of existing 4G LTE systems into 5G systems. Compared to the evolved packet core (EPC), the network core for existing 4G systems, 5GC supports the following differentiated features:

[0030] First, 5GC introduces network slicing. As a 5G requirement, 5GC must support various terminal types and services (e.g., eMBB, URLLC, or mMTC services). Each type of service has different requirements for the core network. For example, eMBB services require high data rates, while URLLC services require high reliability and low latency. One technology proposed to meet these diverse service requirements is network slicing.

[0031] Network slicing virtualizes a single physical network to create multiple logical networks. Each network slice instance (NSI) can have different characteristics. Therefore, each NSI can satisfy diverse service requirements by possessing a network function (NF) tailored to its characteristics. If each terminal is assigned an NSI that matches the characteristics of the service it requires, multiple 5G services can be efficiently supported.

[0032] Second, 5GC can facilitate support for the network virtualization paradigm by separating mobility management and session management functions. In 4G LTE (long term evolution), services were provided through signaling exchanges with a single core device called the mobility management entity (MME), which was responsible for registration, authentication, mobility management, and session management for all terminals. However, in 5G, the number of terminals increases explosively, and the mobility and traffic / session characteristics that must be supported for each terminal type become more specialized. Therefore, supporting all functions with a single device like the MME inevitably reduces scalability by adding entities for each required function. Therefore, various functions are being developed based on a structure that separates mobility management and session management functions to improve scalability in terms of functional / implementation complexity and signaling load of the core device responsible for the control plane.

[0033] Hereinafter, various embodiments will be described in detail with reference to the accompanying drawings. Furthermore, when describing embodiments of the present disclosure, detailed descriptions of related known functions or configurations will be omitted if they are deemed to unnecessarily obscure the gist of the embodiments. Furthermore, the terms described below are defined in consideration of their functions in the embodiments, and may vary depending on the intent or custom of the user or operator. Therefore, their definitions should be based on the contents throughout this specification.

[0034] For the same reason, some components in the attached drawings are exaggerated, omitted, or schematically depicted. Furthermore, the dimensions of each component do not entirely reflect its actual size. Identical or corresponding components in each drawing are assigned the same reference numbers.

[0035] The advantages and features of the present disclosure, and methods for achieving them, will become clearer with reference to the embodiments described in detail below together with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below and may be implemented in various different forms. These embodiments are provided solely to ensure that the present disclosure is complete and to fully inform those skilled in the art of the scope of the disclosure, and the present disclosure is defined only by the scope of the claims. Like reference numerals designate like elements throughout the specification.

[0036] At this time, it will be understood that each block of the processing flowchart drawings and combinations of the flowchart drawings can be performed by computer program instructions. These computer program instructions can be installed in a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing equipment, so that the instructions executed by the processor of the computer or other programmable data processing equipment create a means for performing the functions described in the flowchart block(s). These computer program instructions can also be stored in a computer-available or computer-readable memory that can direct a computer or other programmable data processing equipment to implement the functions in a specific manner, so that the instructions stored in the computer-available or computer-readable memory can also produce a manufactured item that includes an instruction means for performing the functions described in the flowchart block(s). Since the computer program instructions may be installed on a computer or other programmable data processing device, a series of operational steps may be performed on the computer or other programmable data processing device to create a computer-executable process, and the instructions that cause the computer or other programmable data processing device to perform the steps for performing the functions described in the flowchart block(s) may also provide steps for performing the functions described in the flowchart block(s).

[0037] Additionally, each block may represent a module, segment, or portion of code that contains one or more executable instructions for performing a specific logical function(s). It should also be noted that in some alternative implementation examples, the functions described in the blocks may occur out of order. For example, two blocks depicted in succession may actually be executed substantially concurrently, or the blocks may sometimes be executed in reverse order, depending on their respective functions.

[0038] Here, the term '~ unit' used in various embodiments of the present disclosure means a software or hardware component such as an FPGA or ASIC, and the '~ unit' can perform certain roles. However, the '~ unit' is not limited to software or hardware. The '~ unit' may be configured to be on an addressable storage medium and may be configured to play one or more processors. Accordingly, as an example, the '~ unit' may include components such as software components, object-oriented software components, class components, and task components, processes, functions, properties, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functions provided within the components and '~ units' may be combined into a smaller number of components and '~ units' or further separated into additional components and '~ units'. Additionally, components and '~parts' may be implemented to regenerate one or more CPUs within a device or secure multimedia card.

[0039] Hereinafter, a base station is an entity that performs resource allocation of a terminal, and may be at least one of an eNode B (eNB), a Node B, a BS (base station), a RAN (radio access network), an AN (access network), a RAN node, a NR NB, a gNB, a wireless access unit, a base station controller, or a node on a network. The terminal may include a UE (user equipment), an MS (mobile station), a cellular phone, a smartphone, a computer, or a multimedia system capable of performing a communication function. In various embodiments of the present disclosure, a case where the terminal is a UE will be described as an example. In addition, although various embodiments of the present disclosure are described below using a system based on LTE, LTE-A, or NR as an example, various embodiments of the present disclosure may be applied to other communication systems having a similar technical background or channel type. In addition, various embodiments of the present disclosure may be applied to other communication systems with some modifications within a range that does not significantly depart from the scope thereof at the discretion of a person having skilled technical knowledge.

[0040] The terms used in the following description to identify connection nodes, terms referring to network entities, terms referring to messages, terms referring to interfaces between network entities, terms referring to various identification information, etc. are provided as examples for convenience of explanation. Therefore, the present disclosure is not limited to the terms described below, and other terms referring to objects with equivalent technical meanings may be used.

[0041] Additionally, while this disclosure describes various embodiments using terminology used in certain communication standards (e.g., 3rd Generation Partnership Project (3GPP)), these are merely illustrative examples. The various embodiments of this disclosure can be easily modified and applied to other communication systems. Below, some terms used in the core network of this disclosure are predefined.

[0042] AMF Access and Mobility Management Function

[0043] CN Core Network

[0044] CNF Containerized Network Function

[0045] DNN Data Network Name

[0046] PCF Policy Control Function

[0047] HSS Home Subscriber Server

[0048] SMF Session Management Function

[0049] UDM User Data Management

[0050] UPF User Plane Function

[0051] CNF Containerized Network Function

[0052] VNF Virtual Network Function

[0053]

[0054] FIG. 1A is a diagram illustrating a communication network including core network entities in a wireless communication system according to embodiments of the present disclosure. A 5G mobile communication network may be configured to include a 5G user equipment (UE) (110), a 5G radio access network (RAN) (120), and a 5G core network.

[0055] The 5G core network may be configured to include network functions such as an access and mobility management function (AMF) (150) that provides a mobility management function of UE, a session management function (SMF) (160) that provides a session management function, a user plane function (UPF) (170) that performs a data transfer role, a policy control function (PCF) (180) that provides a policy control function, a unified data management (UDM) (153) that provides a data management function such as subscriber data and policy control data, or a unified data repository (UDR) that stores data of various network functions.

[0056] Referring to FIG. 1A, a user equipment (UE) (110) may communicate with a base station (e.g., an eNB, a gNB) via a wireless channel, i.e., an access network. In some embodiments, the UE (110) may be a device used by a user and configured to provide a user interface (UI). As an example, the UE (110) may be a terminal mounted (equipment) on a vehicle for driving. In some other embodiments, the UE (110) may be a device that performs machine type communication (MTC) that operates without user intervention, or may be an autonomous vehicle. UE may be referred to as a 'terminal', 'vehicle terminal', 'user equipment (UE)', 'mobile station', 'subscriber station', 'remote terminal', 'wireless terminal', or 'user device' or other terms having equivalent technical meanings, other than electronic devices. As the terminal, in addition to the UE, a customer-premises equipment (CPE) or a dongle-type terminal may be used. The CPE, while connected to the NG-RAN node like the UE, may also provide a network to other communication devices (e.g., a laptop).

[0057] Referring to FIG. 1A, the AMF (150) provides a function for connection and mobility management per terminal (110), and basically, one AMF (150) can be connected to one terminal (110). Specifically, the AMF (150) can perform at least one of signaling between core network nodes for mobility between 3GPP access networks, an interface (N2 interface) between wireless access networks (e.g., 5G RAN) (120), NAS signaling with the terminal (110), identification of the SMF (160), and provision of transmission of session management (SM) messages between the terminal (110) and the SMF (160). Some or all of the functions of the AMF (150) can be supported within a single instance of one AMF (150).

[0058] Referring to FIG. 1A, the SMF (160) provides a session management function, and when the terminal (110) has multiple sessions, each session may be managed by a different SMF (160). Specifically, the SMF (160) may perform at least one of the following functions: session management (e.g., session establishment, modification, and release, including tunnel maintenance between the UPF (170) and the access network node), selection and control of UP (user plane) functions, traffic steering setup for routing traffic to an appropriate destination in the UPF (170), termination of the SM portion of NAS messages, downlink data notification (DDN), and initiation of AN-specific SM information (e.g., delivery to the access network via the N2 interface via the AMF (150)). Some or all of the functions of the SMF (160) may be supported within a single instance of one SMF (160).

[0059] In the 3GPP system, conceptual links connecting NFs within a 5G system may be referred to as reference points. Reference points may also be referred to as interfaces. The following exemplifies reference points (hereafter, interchangeably referred to as interfaces) included in the 5G system architecture represented across various embodiments of the present disclosure.

[0060] - N1: Reference point between UE (110) and AMF (150)

[0061] - N2: Reference point between (R)AN(120) and AMF(150)

[0062] - N3: Reference point between (R)AN(120) and UPF(170)

[0063] - N4: Reference point between SMF (160) and UPF (170)

[0064] - N5: Reference point between PCF (180) and AF (130)

[0065] - N6: Reference point between UPF (170) and DN (140)

[0066] - N7: Reference point between SMF (160) and PCF (180)

[0067] - N8: Reference point between UDM (153) and AMF (150)

[0068] - N9: Reference point between two core UPFs (170)

[0069] - N10: Reference point between UDM (153) and SMF (160)

[0070] - N11: Reference point between AMF (150) and SMF (160)

[0071] - N12: Reference point between AMF (150) and authentication server function (AUSF) (151)

[0072] - N13: Reference point between UDM (153) and authentication server function (151)

[0073] - N14: Reference point between two AMFs (150)

[0074] - N15: For non-roaming scenarios, reference point between PCF (180) and AMF (150), for roaming scenarios, reference point between PCF (180) and AMF (150) within the visited network.

[0075]

[0076] FIG. 1B is a diagram illustrating a wireless environment including a core network in a wireless communication system according to embodiments of the present disclosure. Referring to FIG. 1B, the wireless communication system includes a radio access network (RAN) (120) and a core network (CN).

[0077] The wireless access network (120) is a network that is directly connected to a user device, for example, a terminal (110), and is an infrastructure that provides wireless access to the terminal (110). The wireless access network (120) includes a set of a plurality of base stations including a base station (125), and the plurality of base stations can communicate through interfaces formed between each other. At least some of the interfaces between the plurality of base stations can be wired or wireless. The base station (125) can have a structure that is divided into a central unit (CU) and a distributed unit (DU). In this case, one CU can control a plurality of DUs. The base station (125) can be referred to as an 'access point (AP)', 'next generation node B (gNB)', '5th generation node (5G node)', 'wireless point', 'transmission / reception point (TRP)', or other terms having an equivalent technical meaning thereto in addition to the base station. The terminal (110) connects to a wireless access network (120) and communicates with a base station (125) via a wireless channel. The terminal (110) may be referred to as a 'user equipment (UE)', a 'mobile station', a 'subscriber station', a 'remote terminal', a 'wireless terminal', a 'user device', or other terms having an equivalent technical meaning.

[0078] The core network is a network that manages the entire system, controls the wireless access network (120), and processes data and control signals for terminals (110) transmitted and received through the wireless access network (120). The core network performs various functions, such as controlling the user plane and control plane, processing mobility, managing subscriber information, billing, and interworking with other types of systems (e.g., long term evolution (LTE) system). In order to perform the various functions described above, the core network may include a number of functionally separated entities having different network functions (NFs). For example, the core network (200) may include an access and mobility management function (AMF) (150), a session management function (SMF) (160), a user plane function (UPF) (170), a policy and charging function (PCF) (180), a network repository function (NRF) (159), a unified data management (UDM) (153), a network exposure function (NEF) (155), and a unified data repository (UDR) (157).

[0079] The terminal (110) is connected to the wireless access network (120) and accesses the AMF (150) that performs the mobility management function of the core network. The AMF (150) is a function or device that is in charge of both the connection to the wireless access network (120) and the mobility management of the terminal (110). The SMF (160) is an NF that manages sessions. The AMF (150) is connected to the SMF (160), and the AMF (150) routes session-related messages for the terminal (110) to the SMF (160). The SMF (160) is connected to the UPF (170) to allocate user plane resources to be provided to the terminal (110), and establishes a tunnel for transmitting data between the base station (125) and the UPF (170). PCF (180) controls information related to policy and charging for the session used by the terminal (110).

[0080] The NRF (159) stores information about NFs installed in a mobile communication operator network and performs the function of notifying the stored information. The NRF (159) can be connected to all NFs. When each NF starts operating in the operator network, it registers with the NRF (159) to notify the NRF (159) that the NF is operating within the network. The UDM (153) is an NF that performs a role similar to the HSS (home subscriber server) of a 4G network, and stores the subscription information of the terminal (110) or the context used by the terminal (110) within the network.

[0081] The NEF (155) connects a third-party server and an NF within the 5G mobile communication system. It also provides data to, updates, or acquires data from the UDR (157). The UDR (157) stores subscription information for the terminal 120, policy information, data exposed externally, or information required by a third-party application. Furthermore, the UDR (157) provides stored data to other NFs.

[0082]

[0083] FIG. 2A is a diagram illustrating an example of the functional structure of a terminal according to embodiments of the present disclosure. The configuration illustrated in FIG. 2A can be understood as the configuration of a terminal (110). Terms such as "... unit" and "... device" used hereinafter refer to a unit that processes at least one function or operation, which can be implemented using hardware, software, or a combination of hardware and software.

[0084] Referring to FIG. 2a, the terminal includes a communication unit (205), a storage unit (210), and a control unit (215).

[0085] The communication unit (205) performs functions for transmitting and receiving signals via a wireless channel. For example, the communication unit (205) performs a conversion function between a baseband signal and a bit stream according to the physical layer specifications of the system. For example, when transmitting data, the communication unit (205) generates complex symbols by encoding and modulating a transmission bit stream. In addition, when receiving data, the communication unit (205) restores a reception bit stream by demodulating and decoding the baseband signal. In addition, the communication unit (205) upconverts a baseband signal into an RF band signal and transmits it through an antenna, and downconverts an RF band signal received through the antenna into a baseband signal. For example, the communication unit (205) may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a DAC, an ADC, etc.

[0086] In addition, the communication unit (205) may include a plurality of transmit / receive paths. Furthermore, the communication unit (205) may include at least one antenna array composed of a plurality of antenna elements. In terms of hardware, the communication unit (205) may be composed of digital circuits and analog circuits (e.g., radio frequency integrated circuits (RFIC)). Here, the digital circuits and analog circuits may be implemented in a single package. In addition, the communication unit (205) may include a plurality of RF chains. Furthermore, the communication unit (205) may perform beamforming.

[0087] The communication unit (205) transmits and receives signals as described above. Accordingly, all or part of the communication unit (205) may be referred to as a "transmitter," a "receiver," or a "transmitting and receiving unit." Furthermore, in the following description, transmission and reception performed via a wireless channel are used to mean that the communication unit (205) performs the processing described above.

[0088] The storage unit (210) stores data such as basic programs, application programs, and setting information for the operation of the terminal. The storage unit (210) may be composed of volatile memory, non-volatile memory, or a combination of volatile and non-volatile memory. In addition, the storage unit (210) provides stored data upon request from the control unit (215).

[0089] The control unit (215) controls the overall operations of the terminal. For example, the control unit (215) transmits and receives signals through the communication unit (205). In addition, the control unit (215) records and reads data in the storage unit (210). In addition, the control unit (215) can perform functions of the protocol stack required by the communication standard. To this end, the control unit (215) may include at least one processor or microprocessor, or may be a part of a processor. In addition, a part of the communication unit (205) and the control unit (215) may be referred to as a CP (communication processor). According to various embodiments, the control unit (215) may control to perform synchronization using a wireless communication network. For example, the control unit (215) may control the terminal to perform operations according to various embodiments described below.

[0090] According to various embodiments of the present disclosure, a terminal may be composed of a mobile equipment (ME) and a universal mobile telecommunications service (UMTS) subscriber identity module (USIM). The ME may include a mobile terminal (MT) and terminal equipment (TE). The MT may be a part where a wireless access protocol operates, and the TE may be a part where a control function operates. For example, in the case of a wireless communication terminal (e.g., a mobile phone), the MT and the TE may be integrated, and in the case of a laptop, the MT and the TE may be separate. The present disclosure may express the ME and the USIM as distinct entities depending on the operation of each component, but is not limited thereto, and may express the ME and the USIM as a terminal (e.g., UE) including the ME, or it is of course possible to describe various embodiments of the present disclosure by expressing the ME as a terminal.

[0091]

[0092] FIG. 2B is a diagram illustrating an example of the functional structure of a base station according to embodiments of the present disclosure. The configuration illustrated in FIG. 2B can be understood as the configuration of a base station (120). Terms such as "... unit" and "... unit" used hereinafter refer to a unit that processes at least one function or operation, which can be implemented by hardware, software, or a combination of hardware and software.

[0093] Referring to FIG. 2b, the base station includes a wireless communication unit (235), a backhaul communication unit (220), a storage unit (225), and a control unit (230).

[0094] The wireless communication unit (235) performs functions for transmitting and receiving signals via a wireless channel. For example, the wireless communication unit (235) performs a conversion function between baseband signals and bit streams according to the physical layer specifications of the system. For example, when transmitting data, the wireless communication unit (235) encodes and modulates the transmitted bit stream to generate complex symbols. Additionally, when receiving data, the wireless communication unit (235) restores the received bit stream by demodulating and decoding the baseband signal.

[0095] In addition, the wireless communication unit (235) upconverts a baseband signal into an RF (radio frequency) band signal and transmits it through an antenna, and downconverts an RF band signal received through the antenna into a baseband signal. To this end, the wireless communication unit (235) may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a digital to analog convertor (DAC), an analog to digital convertor (ADC), etc. In addition, the wireless communication unit (235) may include a plurality of transmission and reception paths. Furthermore, the wireless communication unit (235) may include at least one antenna array composed of a plurality of antenna elements.

[0096] In terms of hardware, the wireless communication unit (235) may be composed of a digital unit and an analog unit, and the analog unit may be composed of a plurality of sub-units depending on operating power, operating frequency, etc. The digital unit may be implemented with at least one processor (e.g., a digital signal processor (DSP)).

[0097] The wireless communication unit (235) transmits and receives signals as described above. Accordingly, all or part of the wireless communication unit (235) may be referred to as a "transmitter," a "receiver," or a "transceiver." Furthermore, in the following description, transmission and reception performed via a wireless channel are used to mean that the wireless communication unit (235) performs the processing described above.

[0098] The backhaul communication unit (220) provides an interface for communicating with other nodes within the network. That is, the backhaul communication unit (220) converts a bit string transmitted from a base station to another node, such as another access node, another base station, an upper node, a core network, etc., into a physical signal, and converts a physical signal received from another node into a bit string.

[0099] The storage unit (225) stores data such as basic programs, application programs, and setting information for the operation of the base station. The storage unit (225) may be composed of volatile memory, non-volatile memory, or a combination of volatile and non-volatile memory. In addition, the storage unit (225) provides stored data upon request from the control unit (230).

[0100] The control unit (230) controls the overall operations of the base station. For example, the control unit (230) transmits and receives signals through the wireless communication unit (235) or the backhaul communication unit (220). In addition, the control unit (230) records and reads data in the storage unit (225). In addition, the control unit (230) can perform the functions of the protocol stack required by the communication standard. According to another implementation example, the protocol stack can be included in the wireless communication unit (235). For this purpose, the control unit (230) can include at least one processor. According to various embodiments, the control unit (230) can control to perform synchronization using a wireless communication network. For example, the control unit (230) can control the base station to perform operations according to various embodiments described below.

[0101]

[0102] FIG. 2C is a diagram illustrating an example of the functional structure of a core network object according to embodiments of the present disclosure. It illustrates the configuration of a core network object in a wireless communication system according to various embodiments of the present disclosure. The configuration illustrated in FIG. 2C can be understood as a configuration of a device having the function of at least one of the network entities including the AMF (150) of FIG. 1. Terms such as "... unit" and "... device" used hereinafter mean a unit that processes at least one function or operation, and this can be implemented by hardware, software, or a combination of hardware and software.

[0103] Referring to the above drawing 2c, the core network object is configured to include a communication unit (240), a storage unit (245), and a control unit (250).

[0104] The communication unit (240) provides an interface for performing communication with other devices within the network. That is, the communication unit (240) converts a bit string transmitted from the core network object to another device into a physical signal, and converts a physical signal received from another device into a bit string. That is, the communication unit (240) can transmit and receive signals. Accordingly, the communication unit (240) may be referred to as a modem, a transmitter, a receiver, or a transceiver. In this case, the communication unit (240) enables the core network object to communicate with other devices or systems via a backhaul connection (e.g., wired backhaul or wireless backhaul) or via a network.

[0105] The storage unit (245) stores data such as basic programs, application programs, and setting information for the operation of the core network object. The storage unit (245) may be composed of volatile memory, non-volatile memory, or a combination of volatile and non-volatile memory. In addition, the storage unit (245) provides the stored data upon request from the control unit (250).

[0106] The control unit (250) controls the overall operations of the core network object. For example, the control unit (250) transmits and receives signals through the communication unit (240). In addition, the control unit (250) records and reads data from the storage unit (245). For this purpose, the control unit (250) may include at least one processor. According to various embodiments of the present disclosure, the control unit (250) may control synchronization using a wireless communication network. For example, the control unit (250) may control the core network object to perform operations according to various embodiments described below.

[0107]

[0108] The terms used in the following description to identify connection nodes, terms referring to network entities, terms referring to messages, terms referring to interfaces between network entities, and terms referring to various identification information are provided as examples for convenience of explanation. Therefore, the present disclosure is not limited to the terms described below, and other terms referring to objects with equivalent technical meanings may be used.

[0109] For convenience of explanation, this disclosure uses terms and names defined in the 5GS (5G system) and NR (new radio) standards, the most recent standards defined by the 3GPP organization among the existing communication standards. However, this disclosure is not limited to these terms and names and can be equally applied to wireless communication networks conforming to other standards. In particular, this disclosure can be applied to 3GPP 5th generation mobile communication standards (e.g., 5GS and NR).

[0110] FIG. 3 is a diagram illustrating a hierarchy of encryption keys generated by a terminal and a network for secure communication according to an embodiment of the present disclosure.

[0111] The encryption key actually used by the terminal and the network for communication is an encryption key derived through several steps based on the root key that both parties possess in advance.

[0112] The reason why the root key shared between the terminal and the network is not used immediately, but a new key to be used for communication is derived is as follows. The root key shared between the terminal and the network is security information stored in the SIM on the terminal side, and security information stored in the UDM / ARF on the network side, and is a value that does not change until the SIM is replaced. In other words, authentication between the terminal and the network occurs multiple times while the SIM is in use, and the root key is an immutable value during this process. Therefore, if the root key value is used as an encryption key for communication, the key value for secure communication is immutable, which weakens the security level. To increase the security level, a new encryption key must be generated each time authentication occurs and this value must be used for communication. For this reason, the terminal and the network do not use the existing root key value as a key for encrypted communication directly, but derive a new key using the root key value. This process can be achieved by deriving a new encryption key using the root key value and a random value (hereinafter referred to as RAND) that changes with each authentication. Simply put, the 'root key' and 'RAND' can be used as materials to derive the encryption key that the terminal and network will actually use for secure communication after authentication, and accordingly, the encryption key can be different for each authentication.

[0113] However, the above derivation process can be carried out not in a single step but in multiple stages. In other words, it can be carried out through multiple layers. The reason for this multi-stage process is as follows. The terminal consists of a SIM and an ME, and the network consists of various entities such as the UDM, ARPF, AUSF, and SEAF. Each entity has different security levels and roles, and their roles in the process of deriving the encryption key also differ. Therefore, because the encryption key must be formed through collaboration among multiple entities, the encryption key derivation process takes place in multiple stages, and the keys generated as a result have layers.

[0114] As described above, Figure 3 is a diagram illustrating the layers of the keys described above. A detailed description thereof is provided below.

[0115] First, let me explain from the terminal's perspective.

[0116] - The terminal can be composed of SIM and ME.

[0117] - The SIM may have the root key value described above. The root key may be referred to as K.

[0118] - SIM can derive encryption key values ​​called CK and IK using the above K value and the RAND value described above.

[0119] - SIM can transmit the above CK and IK to ME.

[0120] - ME can generate an encryption key value called K_SEAF using the received CK and IK values.

[0121] Next, let's explain from the network's perspective.

[0122] - The network can consist of UDM, ARPF, AUSF and SEAF.

[0123] - SEAF can be a logical entity or function provided by AMF for security purposes.

[0124] - UDM / ARPF may have the root key value K described above.

[0125] - UDM / ARPF can derive encryption key values ​​called CK and IK using the above K value and the RAND value described above.

[0126] - UDM / ARPF can pass the above CK and IK values ​​to UDM / ARPF / AUSF.

[0127] - UDM / ARPF / AUSF can generate an encrypted value called K_SEAF using the received CK and IK values.

[0128] - UDM / ARPF / AUSF can transmit the above generated K_SEAF to SEAF.

[0129] Through the process described above, the terminal and the network may have come to possess a common encryption key K_SEAF.

[0130] The terminal and the network can use the above K_SEAF to derive additional encryption keys for lower layers not shown in the drawing. The newly derived keys may be encryption keys to be used in the 'terminal and AMF' and / or the 'terminal and gNB'. The derived keys may be keys for encryption purposes (i.e., encryption / decryption) and / or keys for integrity protection.

[0131] The encryption keys described above may have different security levels. For example, the encryption keys described above may have two different security levels. For example, an encryption key supporting a higher security level may have a longer key length, and an encryption key supporting a lower security level may have a shorter key length. For example, an encryption key supporting a higher security level may have key values ​​suitable for a 256-bit encryption algorithm, and an encryption key supporting a lower security level may have key values ​​suitable for a 128-bit encryption algorithm.

[0132] A SIM supporting a high security level may be able to provide both high-security and low-security encryption keys to the ME simultaneously. A SIM supporting a low security level may only be able to provide low-security encryption keys to the ME.

[0133] An ME supporting a high security level can simultaneously support both high-security encryption algorithms using high-security encryption keys and low-security encryption algorithms using low-security encryption keys. An ME supporting a low security level can only support low-security encryption algorithms using low-security encryption keys.

[0134] A network supporting a high security level can simultaneously derive both high-security and low-security encryption keys. Furthermore, a network supporting a high security level can simultaneously support both high-security encryption algorithms that use high-security encryption keys and low-security encryption algorithms that use low-security encryption keys. A network supporting a low security level can only derive low-security encryption keys. Furthermore, a network supporting a low security level can only support low-security encryption algorithms that use low-security encryption keys.

[0135]

[0136] FIG. 4 is a diagram illustrating an authentication process of a terminal and a network and a shared key formation process for secure communication according to one embodiment of the present disclosure.

[0137] The above process is called primary authentication, and through this process, the terminal and the network authenticate each other and share an encryption key that will be used for secure communication between the terminal and the network. For a detailed description of the encryption key used for secure communication, refer to Figure 3.

[0138] The terminal (400) illustrated in FIG. 4 may be composed of a SIM (410) and an ME (420). The network illustrated in FIG. 4 may be composed of a SEAF (430) and an AUSF / UDM / ARPF (440).

[0139] Below, each step to be performed in Fig. 4 will be individually described.

[0140] At step 401, ME (420) may perform one or more of the following processes.

[0141] - ME (420) can send information that can identify the UE to SEAF (430). The information may be SUCI (SUbscription Concealed Identifier) ​​or 5G-GUTI (Globally Unique Temporary Identifier).

[0142] - ME (420) can transmit the encryption algorithm it supports to SEAF (430). The above information can be referred to as security capability.

[0143] At step 402, SEAF (430) may perform one or more of the following processes.

[0144] - SEAF (430) can transmit information that can identify a terminal requesting authentication with AUSF / UDM / ARPF (440). The information may be SUCI or SUPI (Subscription Permanent Identity) corresponding to the terminal.

[0145] At step 403, AUSF / UDM / ARPF (440) may perform one or more of the following processes.

[0146] - AUSF / UDM / ARPF (440) can identify the SIM requesting authentication based on the information of the received terminal.

[0147] - AUSF / UDM / ARPF (440) can verify the cryptographic root key held by the SIM requesting authentication. The root key may be K described in Fig. 3.

[0148] - AUSF / UDM / ARPF (440) can transmit information necessary for authentication and shared key formation to SEAF (430). This information may be referred to as AV. AV may include the RAND value described in FIG. 3.

[0149] At step 404, SEAF (430) may perform one or more of the following processes.

[0150] - SEAF (430) can transmit all or part of the AV value received in step 403 to ME (420).

[0151] - The value transmitted above may include a RAND value.

[0152] At step 405, ME (420) may perform one or more of the following processes.

[0153] - ME (420) can transmit all or part of the AV value received in step 404 to SIM (410).

[0154] - The value transmitted above may include a RAND value.

[0155] At step 406, SIM (410) may perform one or more of the following processes.

[0156] - SIM (410) can generate CK and IK using the received RAND and K it possesses. For a description of CK and IK, refer to Fig. 3.

[0157] - SIM (410) can transmit the generated CK and IK to ME (420).

[0158] At step 407, one or more of the following processes may be performed.

[0159] - ME (420) can derive K_SEAF using CK and IK received in step 406. In addition, it can generate encryption and / or integrity protection keys to be used with AMF and / or gNB using the derived K_SEAF.

[0160] - AUSF / UDM / ARPF (440) can generate K_SEAF and transmit it to SEAF (430). The K_SEAF can be used to generate encryption and / or integrity protection keys that the AMF and / or gNB will use for secure communication with the terminal.

[0161] As described in the introduction of Figure 3, each entity comprising the terminal and network can support either a high or low level of security. However, if the security levels of these entities differ, the primary authentication method presented in this diagram (the currently used method) may have difficulty functioning properly. Consider the following example.

[0162] - SIM: Supports high security level

[0163] ME: Support for low security levels

[0164] SEAF / AUSF / UDM / ARPF: High security level support

[0165] In this case, the AUSF / UDM / ARPF (440), which has identified the SIM with the information received in step 402, will transmit the AV for generating a high-security level key to the SEAF (430) in step 403 based on the fact that the SIM supports a high security level. This value is transmitted to the SIM (410) through steps 404 and 405, and the SIM (410) can transmit the high-security level CK and IK to the ME (420) in step 406. However, the ME (420) supports a low security level, and since the ME (420) supporting a low security level as described in FIG. 3 cannot apply a high-security level encryption key, the authentication process cannot be performed normally.

[0166] The above example is just one example, and there may be various cases where problems arise when the security levels of the three entities above are different.

[0167] In the following sections, several methods to address these issues will be presented.

[0168]

[0169] FIG. 5 is a diagram illustrating an authentication process and a shared key formation process for secure communication between a terminal and a network that may have different security levels according to an embodiment of the present disclosure.

[0170] The above process is an improved form of primary authentication, allowing the terminal and network to authenticate each other and share an encryption key to be used for secure communication between the terminal and the network. For a detailed description of the encryption key used for secure communication, refer to Figure 3.

[0171] The terminal (500) illustrated in FIG. 5 may be comprised of a SIM (510) and an ME (520). The network illustrated in FIG. 5 may be comprised of a SEAF (530) and an AUSF / UDM / ARPF (540). The SIM, ME, and SEAF may each support a high or low security level. For a detailed functional description of the SIM, ME, and SEAF supporting a high or low security level, refer to FIGS. 3 and 4.

[0172] Below, each step to be performed in Fig. 5 will be individually described.

[0173] In step 501, ME (520) may perform one or more of the following processes.

[0174] - ME (520) can send information that can identify the UE to SEAF (530). The information may be SUCI or 5G-GUTI.

[0175] - The ME (520) can transmit the encryption algorithm it supports to the SEAF (530). The above information may be referred to as security capability. In this case, an ME supporting a high security level may include a high security level algorithm.

[0176] At step 502, SEAF (530) may perform one or more of the following processes.

[0177] - SEAF (530) can transmit information that can identify the terminal requesting authentication with AUSF / UDM / ARPF (540). The information may be SUCI or SUPI corresponding to the terminal.

[0178] At this time, if SEAF (530) supports a high security level, the following process may be additionally performed.

[0179] - SEAF (530) can transmit information (indicated as indicator 1 in the drawing) notifying that the algorithm supported by ME (520) received in step 501 includes a high security level algorithm to AUSF / UDM / ARPF (540). The information can be included as a parameter of a message sent by SEAF (530) to AUSF / UDM / ARPF (540) in step 502.

[0180] At step 503, AUSF / UDM / ARPF (540) may perform one or more of the following processes.

[0181] - AUSF / UDM / ARPF (540) can identify the SIM requesting authentication based on the information of the received terminal.

[0182] - AUSF / UDM / ARPF (540) can verify the cryptographic root key held by the SIM requesting authentication. The root key may be K described in Fig. 3.

[0183] - AUSF / UDM / ARPF (540) can transmit information necessary for authentication and shared key formation to SEAF (530). This information may be referred to as AV. AV may include the RAND value described in FIG. 3.

[0184] - If the information on the SIM is verified to support a high security level and indicator 1 is received in step 502, the AUSF / UDM / ARPF (540) can be configured with the information required to derive a high security level encryption key when generating an AV.

[0185] - If the above AV is composed of information necessary for deriving a high-security level encryption key, the AUSF / UDM / ARPF (540) may transmit information notifying this fact (indicated as indicator 2 in the drawing) to the SEAF (530). The above information may be included as a parameter of the message sent by the AUSF / UDM / ARPF (540) in step 503.

[0186] At step 504, SEAF (530) may perform one or more of the following processes.

[0187] - SEAF (530) can transmit all or part of the AV value received in step 503 to ME (520).

[0188] - The value transmitted above may include a RAND value.

[0189] At this time, if SEAF (530) supports a high security level, the following process may be additionally performed.

[0190] - If SEAF (530) receives indicator 2 in step 503, SEAF (530) can transmit information (indicated as indicator 3 in the drawing) notifying ME (520) of this fact. The information can be included as a parameter of the message sent by SEAF (530) in step 504.

[0191] At step 505, ME (520) may perform one or more of the following processes.

[0192] - ME (520) can transmit all or part of the AV value received in step 504 to SIM (510).

[0193] - The value transmitted above may include a RAND value.

[0194] At this time, if ME (520) supports a high security level, the following process may be additionally performed.

[0195] - If the ME (520) receives indicator 3 in step 504, the ME (520) can transmit information (indicated as indicator 4 in the drawing) notifying the SIM (510) of this fact. The information can be included as a parameter of the message sent by the ME (520) in step 505.

[0196] At step 506, SIM (510) may perform one or more of the following processes.

[0197] - SIM (510) can generate CK and IK using the received RAND and its own K. For a description of CK and IK, refer to Fig. 3.

[0198] - SIM (510) can transmit the generated CK and IK to ME (520).

[0199] At this time, if the SIM (510) supports a high security level, the following process may be additionally performed.

[0200] - If the SIM (510) receives the indicator 4 in step 505, the SIM (510) can transmit a CK and IK with a high security level to the ME (520). If the SIM (510) does not receive the indicator 4 in step 505, the SIM (510) can transmit a CK and IK with a low security level to the ME (520).

[0201] At step 507, one or more of the following processes may be performed.

[0202] - ME (520) can derive K_SEAF using CK and IK received in step 506. In addition, it can generate encryption and / or integrity protection keys to be used with AMF and / or gNB using the derived K_SEAF.

[0203] - AUSF / UDM / ARPF (540) can generate K_SEAF and transmit it to SEAF (530). The K_SEAF can be used to generate encryption and / or integrity protection keys that the AMF and / or gNB will use for secure communication with the terminal.

[0204]

[0205] FIG. 6 is a diagram illustrating an authentication process and a shared key formation process for secure communication between a terminal and a network that may have different security levels according to another embodiment of the present disclosure.

[0206] The above process is an improved form of primary authentication, allowing the terminal and network to authenticate each other and share an encryption key to be used for secure communication between the terminal and the network. For a detailed description of the encryption key used for secure communication, refer to Figure 3.

[0207] The terminal (600) illustrated in FIG. 6 may be comprised of a SIM (610) and an ME (620). The network illustrated in FIG. 6 may be comprised of a SEAF (630) and an AUSF / UDM / ARPF (640). The SIM, ME, and SEAF may each support a high or low security level. For a detailed functional description of the SIM, ME, and SEAF supporting a high or low security level, refer to FIGS. 3 and 4.

[0208] Below, each step to be performed in Fig. 6 will be individually described.

[0209] At step 601, if the ME (620) supports a high security level, one or more of the following processes may be performed.

[0210] - ME (620) can transmit information (indicated as indicator 1 in the drawing) to SIM (610) asking whether the SIM supports a high security level.

[0211] In step 602, if the SIM (610) supports a high security level, one or more of the following processes may be performed.

[0212] - If instruction 1 is received in step 601, the SIM (610) can transmit information (indicated as Response in the drawing) to the ME (620) that it supports a high security level.

[0213] In step 603, ME (620) may perform one or more of the following processes.

[0214] - ME (620) can send information that can identify the UE to SEAF (630). The information may be SUCI or 5G-GUTI.

[0215] - ME (620) can transmit the encryption algorithm it supports to SEAF (630). The above information can be referred to as security capability.

[0216] At this time, if SEAF (630) supports a high security level, the following process may be additionally performed.

[0217] - If instruction 1 is received in step 602, the ME (620) can transmit to SEAF (630) a high-security level algorithm. If instruction 1 is not received in step 602, the ME (620) can transmit only a low-level algorithm to SEAF (630).

[0218] At step 604, SEAF (630) may perform one or more of the following processes.

[0219] - SEAF (630) can transmit information that can identify the terminal requesting authentication with AUSF / UDM / ARPF (640). The information may be SUCI or SUPI corresponding to the terminal.

[0220] At this time, if SEAF (630) supports a high security level, the following process may be additionally performed.

[0221] - If the algorithm supported by the ME (620) received in step 603 includes a high security level algorithm, the SEAF (630) can transmit information notifying this fact (indicated as indicator 2 in the drawing) to the AUSF / UDM / ARPF (640). The information can be included as a parameter of a message sent from the SEAF (630) to the AUSF / UDM / ARPF (640) in step 604.

[0222] At step 605, AUSF / UDM / ARPF (640) may perform one or more of the following processes.

[0223] - AUSF / UDM / ARPF (640) can identify the SIM requesting authentication based on the information of the received terminal.

[0224] - AUSF / UDM / ARPF (640) can verify the cryptographic root key held by the SIM requesting authentication. The root key may be K described in Fig. 3.

[0225] - AUSF / UDM / ARPF (640) can transmit information necessary for authentication and shared key formation to SEAF (630). This information may be referred to as AV. AV may include the RAND value described in FIG. 3.

[0226] - If instruction 2 is received in step 604, AUSF / UDM / ARPF (640) can be configured with the information required to derive a high-security level encryption key when generating AV.

[0227] At step 606, SEAF (630) may perform one or more of the following processes.

[0228] - SEAF (630) can transmit all or part of the AV value received in step 605 to ME (620).

[0229] - The value transmitted above may include a RAND value.

[0230] At this time, if SEAF (630) supports a high security level, the following process may be additionally performed.

[0231] - SEAF (630) may transmit information (indicated as indicator 3 in the drawing) notifying that it also supports a high security level if the algorithm supported by the ME received in step 603 includes a high security level algorithm. The above information may be included as a parameter of the message sent by SEAF (630) in step 606.

[0232] At step 607, ME (620) may perform one or more of the following processes.

[0233] - ME (620) can transmit all or part of the AV value received in step 606 to SIM (610).

[0234] - The value transmitted above may include a RAND value.

[0235] At this time, if ME (620) supports a high security level, the following process may be additionally performed.

[0236] - If the ME (620) receives indicator 3 in step 606, the ME (620) can transmit information (indicated as indicator 4 in the drawing) notifying the SIM (610) of this fact. The information can be included as a parameter of the message sent by the ME (620) in step 607.

[0237] At step 608, SIM (610) may perform one or more of the following processes.

[0238] - SIM (610) can generate CK and IK using the received RAND and K it possesses. For a description of CK and IK, refer to Fig. 3.

[0239] - SIM (610) can transmit the generated CK and IK to ME (620).

[0240] At this time, if the SIM (610) supports a high security level, the following process may be additionally performed.

[0241] - If the SIM (610) receives the indicator 4 in step 607, the SIM (610) can transmit a CK and IK with a high security level to the ME (620). If the SIM (610) does not receive the indicator 4 in step 707, the SIM (610) can transmit a CK and IK with a low security level to the ME (620).

[0242] At step 609, one or more of the following processes may be performed.

[0243] - ME (620) can derive K_SEAF using CK and IK received in step 608. In addition, it can generate encryption and / or integrity protection keys to be used with AMF and / or gNB using the derived K_SEAF.

[0244] - AUSF / UDM / ARPF (640) can generate K_SEAF and transmit it to SEAF (630). The K_SEAF can be used to generate encryption and / or integrity protection keys that the AMF and / or gNB will use for secure communication with the terminal.

[0245]

[0246] It should be noted that the configuration diagrams, exemplary diagrams of control / data signal transmission / reception methods, and exemplary diagrams of operational procedures illustrated in FIGS. 1A to 6 are not intended to limit the scope of the embodiments of the present disclosure. That is, not all components, entities, or operational steps described in FIGS. 1A to 6 should be construed as essential components for the implementation of the disclosure, and implementations may be made within a scope that does not detract from the essence of the disclosure even if only some components are included.

[0247] The operations of the embodiments described above can be realized by providing a memory device storing the corresponding program code in any component within the device. That is, the control unit within the device can execute the operations described above by reading and executing the program code stored in the memory device through a processor or a CPU (Central Processing Unit).

[0248] The various components and modules of the entity or terminal device described in the present disclosure may be operated using hardware circuits, such as logic circuits based on complementary metal oxide semiconductors, firmware, software, and / or hardware and firmware and / or software embedded in a machine-readable medium. For example, various electrical structures and methods may be implemented using electrical circuits such as transistors, logic gates, and application-specific semiconductors.

[0249] The methods according to the embodiments described in the claims or specification of the present disclosure may be implemented in the form of hardware, software, or a combination of hardware and software.

[0250] When implemented in software, a computer-readable storage medium storing one or more programs (software modules) may be provided. The one or more programs stored in the computer-readable storage medium are configured for execution by one or more processors within an electronic device. The one or more programs include instructions that cause the electronic device to execute methods according to embodiments described in the claims or specification of the present disclosure.

[0251] These programs (software modules, software) may be stored in random access memory, non-volatile memory including flash memory, read only memory (ROM), electrically erasable programmable read only memory (EEPROM), magnetic disc storage devices, compact disc-ROMs (CD-ROMs), digital versatile discs (DVDs) or other forms of optical storage devices, magnetic cassettes, or may be stored in memories formed by a combination of some or all of these. In addition, each configuration memory may include multiple copies.

[0252] Additionally, the program may be stored on an attachable storage device that is accessible via a communication network, such as the Internet, an intranet, a local area network (LAN), a wide area network (WAN), a storage area network (SAN), or a combination thereof. Such a storage device may be connected to a device implementing an embodiment of the present disclosure via an external port. Additionally, a separate storage device on the communication network may be connected to a device implementing an embodiment of the present disclosure.

[0253] In the specific embodiments of the present disclosure described above, components included in the disclosure are expressed singularly or plurally, depending on the specific embodiment presented. However, the singular or plural expressions are selected to suit the presented situation for convenience of explanation, and the present disclosure is not limited to singular or plural components. Components expressed in plural may be composed of singular elements, or components expressed in singular may be composed of plural elements.

[0254] While the detailed description of this disclosure has described specific embodiments, it should be understood that various modifications are possible without departing from the scope of this disclosure. Therefore, the scope of this disclosure should not be limited to the described embodiments, but should be defined not only by the scope of the claims described below, but also by equivalents thereof.

Claims

1. A method performed by a first network entity in a wireless communication system, A step of receiving first information capable of identifying the UE (User Equipment) from the UE; and A step of transmitting, to a second network entity, second information related to an algorithm supported by the UE and the first network entity based on first information capable of identifying the UE, A method, characterized in that the second information is information notifying that the algorithm supported by the UE and the first network entity includes an algorithm with a high security level.

2. In paragraph 1, A method, characterized in that the first information is associated with an encryption algorithm supported by the UE.

3. In paragraph 1, A method characterized by further comprising the step of receiving third information necessary for deriving a high-security level encryption key related to authentication and shared key generation from the second network entity.

4. In paragraph 3, If the third information is received, the method further includes a step of transmitting all or part of the third information to the UE, The above UE includes a subscriber identity module (SIM) and a mobile equipment (ME), and A method, characterized in that all or part of the third information is transmitted from the ME to the SIM.

5. A method performed by a second network entity in a wireless communication system, A step of receiving, from a first network entity, second information related to an algorithm supported by the UE and the first network entity based on first information capable of identifying the UE, First information capable of identifying the UE is transmitted from the UE to the first network entity, and A method, characterized in that the second information is information notifying that the algorithm supported by the UE and the first network entity includes an algorithm with a high security level.

6. In paragraph 5, A method, characterized in that the first information is associated with an encryption algorithm supported by the UE.

7. In paragraph 5, A method characterized in that it further comprises a step of transmitting to the first network entity third information necessary for deriving a high-security level encryption key related to authentication and shared key generation.

8. In paragraph 7, When the third information is transmitted, all or part of the third information is transmitted from the first network entity to the UE, and The above UE includes a subscriber identity module (SIM) and a mobile equipment (ME), and A method, characterized in that all or part of the third information is transmitted from the ME to the SIM.

9. In a first network entity in a wireless communication system, A transceiver capable of transmitting and receiving at least one signal; and Including a control unit coupled with the above transmitter and receiver, The above control unit: Receive first information that can identify the UE (User Equipment) from the UE, and A second network entity is configured to transmit second information related to an algorithm supported by the UE and the first network entity based on first information capable of identifying the UE; A first network entity, characterized in that the second information is configured to notify that the algorithm supported by the UE and the first network entity includes an algorithm with a high security level.

10. In paragraph 9, A first network entity, characterized in that the first information is associated with an encryption algorithm supported by the UE.

11. In the 9th paragraph, the control unit A first network entity further configured to receive third information necessary for deriving a high-security level encryption key related to authentication and shared key generation from said second network entity.

12. In paragraph 11, If the third information is received, it is further configured to transmit all or part of the third information to the UE, The above UE includes a subscriber identity module (SIM) and a mobile equipment (ME), and A first network entity, characterized in that all or part of the third information is transmitted from the ME to the SIM.

13. In a second network entity in a wireless communication system, A transceiver capable of transmitting and receiving at least one signal; and Including a control unit coupled with the above transmitter and receiver, The above control unit: It is configured to receive, from a first network entity, second information related to an algorithm supported by the UE and the first network entity based on first information capable of identifying the UE (User Equipment), First information capable of identifying the UE is transmitted from the UE to the first network entity, and A second network entity, characterized in that the second information is information notifying that the algorithm supported by the UE and the first network entity includes a high security level algorithm.

14. In paragraph 13, A second network entity, characterized in that the first information is associated with an encryption algorithm supported by the UE.

15. In paragraph 14, Further configured to transmit third information necessary for deriving a high-security level encryption key related to authentication and shared key generation to the above first network entity, When the third information is transmitted, all or part of the third information is transmitted from the first network entity to the UE, and The above UE includes a subscriber identity module (SIM) and a mobile equipment (ME), and A second network entity, characterized in that all or part of the third information is transmitted from the ME to the SIM.

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