Data transmission method and device

Abstract

A data transmission method and device, the method comprising: a first device generating a first random bit sequence, and determining a total amount of key entropy according to the length of the first random bit sequence, the first device determining a key entropy N required for encrypting information entropy according to information entropy and first approximation of the first information bit sequence, the first approximation degree is the ratio of the key entropy required for encrypting the information entropy to the information entropy, and N is a positive integer; and under the condition that the key entropy N required by the encryption information entropy is smaller than or equal to the total key entropy, the first equipment obtains the ciphertext based on the N-bit encryption information entropy in the total key entropy. And the first device sends the ciphertext to the second device. By adopting the design, the first approximation degree is introduced into a communication system as a general index measure of a secure communication scheme, and data transmission meeting specific security performance can be realized through the process.

Description

Data transmission method and device Technical Field

[0001] The embodiments of the present application relate to the field of wireless communications, and in particular to a data transmission method and apparatus. Background Art

[0002] At present, the practical application of secure communication technology is divided into two categories: high-level encryption technology based on cryptography and physical layer security technology.

[0003] Among them, the key indicator for measuring the security of high-level encryption algorithms is security strength. If the security strength is k, it means that the computational complexity of cracking the key is 2 k , or in other words: the best attack algorithm requires computing 2 k times to crack the key, k is a positive integer.

[0004] Key metrics for measuring physical layer security technologies include privacy capacity and bit error rate (BER). Privacy capacity describes the maximum rate that can be securely transmitted. However, this metric is an information-theoretic measure and cannot be measured or estimated in practice. BER describes the bit error floor introduced by a physical layer security solution at a non-target receiver. While this metric is easy to analyze, calculate, and measure, its relationship to security is unclear and cannot be directly correlated with security.

[0005] In summary, there is currently no performance indicator that can make a unified performance evaluation of various secure communication solutions. After defining the performance indicator, how to transmit data based on the performance indicator is a problem worthy of attention.

[0006] Summary of the Invention

[0007] The present application provides a data transmission method and apparatus for implementing data transmission according to defined performance indicators for evaluating various types of secure communication schemes.

[0008] In a first aspect, the present application provides a data transmission method, which includes: a first device generates a first random bit sequence and determines a total amount of key entropy based on the length of the first random bit sequence; the first device determines the key entropy N required to encrypt the information entropy based on the information entropy of the first information bit sequence and a first approximation, wherein the first approximation is the ratio of the key entropy required to encrypt the information entropy to the information entropy, and N is a positive integer; when the key entropy N required to encrypt the information entropy is less than or equal to the total amount of key entropy, the first device encrypts the information entropy based on N bits in the total amount of key entropy to obtain a ciphertext; and the first device sends the ciphertext to the second device.

[0009] Using the above method, the first device determines the key entropy required to encrypt the information entropy based on the information entropy of the first information bit sequence and the first approximation degree. It further determines whether the key entropy required to encrypt the information entropy is less than or equal to the total amount of key entropy generated. If the key entropy required to encrypt the information entropy is less than or equal to the total amount of key entropy generated, the device encrypts the information entropy based on N bits of the total amount of key entropy to obtain ciphertext. Using this design, the first approximation degree is introduced into the communication system as a universal metric for secure communication schemes. This process enables data transmission that meets specific security requirements.

[0010] In one possible design, the first device encrypts the information entropy based on N bits in the total key entropy to obtain a ciphertext. Specifically, but not limited to, the following methods may be used: the first device generates a key stream based on the N bits and the encryption key using a preset encryption algorithm, and XORs the key stream with the information entropy to obtain the ciphertext, where the encryption key is determined based on a root key; or, the first device generates a key stream based on the N bits and preset parameters using a preset encryption algorithm, and XORs the key stream with the information entropy to obtain the ciphertext; or, the first device obtains the ciphertext based on the N bits and the information entropy using a preset encryption algorithm.

[0011] By adopting the above method, it is possible to encrypt the information entropy based on N bits of the total key entropy to obtain the ciphertext.

[0012] In one possible design, the number of bits included in the key stream is the same as the number of bits included in the information entropy.

[0013] In one possible design, the preset encryption algorithm is a symmetric encryption algorithm.

[0014] In one possible design, before the first device generates the first random bit sequence, the first device and the second device determine at least one of the first approximation degree, the key generation algorithm, and the width of the key generation time window.

[0015] With the above design, the communicating parties can determine the first approximation degree, the key generation algorithm and the width of the key generation time window through signaling interaction.

[0016] In one possible design, when the key entropy N required to encrypt the information entropy is greater than the total key entropy, the first device and the second device redetermine at least one of the first approximation degree, the key generation algorithm or the width of the key generation time window.

[0017] With the above design, when the key entropy required to encrypt the information entropy is greater than the total amount of key entropy generated, the communicating parties can redetermine the first approximation degree, the key generation algorithm and the width of the key generation time window through signaling interaction, so that the key entropy required to encrypt the information entropy is less than or equal to the total amount of key entropy generated.

[0018] In one possible design, a first information bit group is composed of the first information bit sequence, and the first information bit group is any one of at least one information bit group to be sent; after the first device encrypts the information entropy based on N bits in the total key entropy to obtain a ciphertext, if the remaining key entropy in the total key entropy is less than N bits and there is an unencrypted information bit group in the at least one information bit group to be sent, the first device generates a second random bit sequence.

[0019] With the above design, when there is an unencrypted information bit group but the remaining key entropy is insufficient, the first device can generate a second random bit sequence to encrypt the unencrypted information bit group.

[0020] In one possible design, the first device is a network device and the second device is a terminal device, or the first device is a terminal device and the second device is a network device.

[0021] In a second aspect, the present application provides a data transmission method, the method comprising:

[0022] The first device generates a random bit sequence in a first time duration and determines a total key entropy based on the length of the random bit sequence, wherein the first time duration is determined based on a first approximation, a second approximation, and a key update period, the first approximation being the ratio of the key entropy required for encrypting information entropy to the information entropy, and the second approximation being the ratio of the key entropy extracted per unit time to the information entropy transmitted per unit time; the first device determines the information entropy to be transmitted in a second time duration based on the first approximation and the total key entropy, wherein the sum of the first time duration and the second time duration is the key update period; the first device encrypts the information entropy to be transmitted based on the total key entropy to obtain a ciphertext; and the first device sends the ciphertext to the second device.

[0023] Using the above method, the total key entropy generated by the first device during the first duration can be used to transmit information entropy determined by the total key entropy and the first approximation during the second duration. The first approximation and the second approximation are introduced into the communication system as universal metrics for secure communication schemes. The frame structure is redesigned, and the first and second durations are determined by the first approximation, the second approximation, and the key update period. This process enables data transmission under given security performance requirements and the security capabilities of the communication system.

[0024] In one possible design, the described T, wherein T represents the key update period, D0 represents the first approximation, and d0 represents the second approximation.

[0025] In one possible design, the first device encrypts the information entropy to be transmitted based on the total key entropy to obtain the ciphertext in the following manner, but not limited to: the first device generates a key stream using a preset encryption algorithm based on the total key entropy and an encryption key, and XORs the key stream with the information entropy to be transmitted to obtain the ciphertext; or the first device generates a key stream using a preset encryption algorithm based on the total key entropy and preset parameters, and XORs the key stream with the information entropy to be transmitted to obtain the ciphertext. Alternatively, the first device obtains the ciphertext using a preset encryption algorithm based on the total key entropy and the information entropy to be transmitted.

[0026] By adopting the above method, the information entropy to be transmitted can be encrypted based on the total amount of key entropy to obtain the ciphertext.

[0027] In one possible design, the number of bits included in the key stream is the same as the number of bits of the information entropy that needs to be transmitted.

[0028] In one possible design, the preset encryption algorithm is a symmetric encryption algorithm.

[0029] In one possible design, before the first device generates a random bit sequence, the first device and the second device determine at least one of the first approximation, the second approximation, a key generation algorithm, and the key update period.

[0030] In one possible design, the first device is a network device and the second device is a terminal device, or the first device is a terminal device and the second device is a network device.

[0031] In a third aspect, the present application provides a data transmission device, the device comprising: a processing module and a transceiver module;

[0032] The processing module is used to generate a first random bit sequence and determine the total amount of key entropy based on the length of the first random bit sequence; determine the key entropy N required to encrypt the information entropy based on the information entropy and a first approximation degree of the first information bit sequence, wherein the first approximation degree is the ratio of the key entropy required to encrypt the information entropy to the information entropy, and N is a positive integer; when the key entropy N required to encrypt the information entropy is less than or equal to the total amount of key entropy, encrypt the information entropy based on N bits in the total amount of key entropy to obtain a ciphertext; the transceiver module is used to send the ciphertext to the second device.

[0033] In one possible design, the processing module is used to encrypt the information entropy based on N bits in the total key entropy to obtain a ciphertext, generate a key stream using a preset encryption algorithm according to the N bits and the encryption key, and XOR the key stream with the information entropy to obtain the ciphertext, where the encryption key is determined based on the root key; or, generate a key stream using a preset encryption algorithm according to the N bits and preset parameters, and XOR the key stream with the information entropy to obtain the ciphertext; or, obtain the ciphertext using a preset encryption algorithm according to the N bits and the information entropy.

[0034] In one possible design, the processing module calls the transceiver module to execute: before generating the first random bit sequence, determining at least one of the first approximation degree, the key generation algorithm, and the width of the key generation time window with the second device.

[0035] In one possible design, the processing module calls the transceiver module to execute: when the key entropy N required to encrypt the information entropy is greater than the total key entropy, redetermine with the second device at least one of the first approximation degree, the key generation algorithm or the width of the key generation time window.

[0036] In one possible design, the first information bit group is composed of the first information bit sequence, and the first information bit group is any one of at least one information bit group to be sent; the processing module is used to generate a second random bit sequence after the first device encrypts the information entropy based on N bits in the total key entropy to obtain a ciphertext, if the remaining key entropy in the total key entropy is less than N bits and there is an unencrypted information bit group in the at least one information bit group to be sent.

[0037] In one possible design, the first device is a network device and the second device is a terminal device, or the first device is a terminal device and the second device is a network device.

[0038] In a fourth aspect, the present application provides a data transmission device, the device comprising: a processing module and a transceiver module;

[0039] The processing module is configured to generate a random bit sequence in a first time duration, and determine a total key entropy based on the length of the random bit sequence, wherein the first time duration is determined based on a first approximation, a second approximation, and a key update period, wherein the first approximation is the ratio of the key entropy required to encrypt information entropy to the information entropy, and the second approximation is the ratio of the key entropy extracted per unit time to the information entropy transmitted per unit time; determine the information entropy to be transmitted in a second time duration based on the first approximation and the total key entropy, wherein the sum of the first time duration and the second time duration is the key update period; and encrypt the information entropy to be transmitted based on the total key entropy to obtain a ciphertext;

[0040] The transceiver module is used to send the ciphertext to the second device.

[0041] In one possible design, the described T, wherein T represents the key update period, D0 represents the first approximation, and d0 represents the second approximation.

[0042] In one possible design, the processing module is used to encrypt the information entropy to be transmitted according to the total key entropy to obtain the ciphertext, and then use a preset encryption algorithm to generate a key stream according to the total key entropy and the encryption key, and XOR the key stream with the information entropy to be transmitted to obtain the ciphertext; or, use a preset encryption algorithm to generate a key stream according to the total key entropy and preset parameters, and XOR the key stream with the information entropy to be transmitted to obtain the ciphertext; or, use a preset encryption algorithm to obtain the ciphertext according to the total key entropy and the information entropy to be transmitted.

[0043] In one possible design, the processing module calls the transceiver module to execute: before the first device generates a random bit sequence, determine at least one of the first approximation, the second approximation, the key generation algorithm and the key update period with the second device.

[0044] In one possible design, the apparatus is a network device and the second device is a terminal device; alternatively, the apparatus is a terminal device and the second device is a network device.

[0045] The technical effects that can be achieved by the above-mentioned third aspect or any possible implementation thereof can refer to the technical effects that can be achieved by the above-mentioned first aspect or any possible implementation thereof. The technical effects that can be achieved by the above-mentioned fourth aspect or any possible implementation thereof can refer to the description of the technical effects that can be achieved by the above-mentioned second aspect or any possible implementation thereof, and they will not be repeated here.

[0046] In a fifth aspect, an embodiment of the present application provides a communication device, which includes: at least one processor and an interface circuit; the interface circuit is used to provide input and / or output of programs or instructions for the at least one processor; the at least one processor is used to execute the program or instructions so that the communication device can implement the method provided in the above-mentioned first aspect or any possible implementation method thereof, or execute the program or instructions so that the communication device can implement the method provided in the above-mentioned second aspect or any possible implementation method thereof.

[0047] In a sixth aspect, an embodiment of the present application provides a computer storage medium, which stores a software program. When the software program is read and executed by one or more processors, it can implement the method provided by the above-mentioned first aspect or any possible implementation method thereof, or it can implement the method provided by the above-mentioned second aspect or any possible implementation method thereof.

[0048] In the seventh aspect, an embodiment of the present application provides a computer program product comprising instructions, which, when executed on a computer, enables the computer to execute the method provided in the above-mentioned first aspect or any possible implementation method thereof, or enables the computer to execute the method provided in the above-mentioned second aspect or any possible implementation method thereof.

[0049] In an eighth aspect, an embodiment of the present application provides a chip system, which includes a processor for supporting the device to implement the functions involved in the above-mentioned first aspect, or for supporting the device to implement the functions involved in the above-mentioned second aspect.

[0050] In one possible design, the chip system further includes a memory for storing necessary program instructions and data. The chip system can be composed of a chip or include a chip and other discrete devices.

[0051] In the ninth aspect, an embodiment of the present application also provides a chip system, which includes a processor and an interface, wherein the interface is used to obtain a program or instruction, and the processor is used to call the program or instruction to implement or support the device to implement the functions involved in the first aspect, or the processor is used to call the program or instruction to implement or support the device to implement the functions involved in the second aspect.

[0052] In one possible design, the chip system further includes a memory for storing program instructions and data necessary for the terminal device. The chip system can be composed of a chip or include a chip and other discrete devices.

[0053] In the tenth aspect, a communication system is provided, which includes a first device and a second device, wherein the first device executes the method provided by the first aspect or any possible design thereof, or the first device executes the method provided by the second aspect or any possible design thereof. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] FIG1 is a schematic diagram of the architecture of a mobile communication system used in an embodiment of the present application;

[0055] FIG2A is a schematic diagram of a key generation algorithm based on channel reciprocity applied in an embodiment of the present application;

[0056] FIG2B is a schematic diagram of a key generation algorithm based on noise entropy (or terminal entropy) applied in an embodiment of the present application;

[0057] FIG3 is a flowchart illustrating an overview of a data transmission method in the present application;

[0058] FIG4A is a schematic diagram showing one of the information entropy of a first information bit sequence encrypted by a first device based on N bits of the total key entropy in the present application;

[0059] FIG4B is a second schematic diagram of the information entropy of the first information bit sequence encrypted by the first device based on N bits of the total key entropy in the present application;

[0060] FIG4C is a third schematic diagram of information entropy of a first information bit sequence encrypted by a first device based on N bits of total key entropy in this application;

[0061] FIG5 is a flowchart illustrating another data transmission method in the present application;

[0062] FIG6 is a schematic diagram of the structure of a data frame in this application;

[0063] FIG7 is a schematic diagram of a structure of a communication device in the present application;

[0064] FIG8 is a second structural diagram of a communication device in this application. DETAILED DESCRIPTION

[0065] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all of the embodiments. The terms "first", "second" and corresponding terminology labels in the specification and claims of this application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way are interchangeable where appropriate, and this is merely a way of distinguishing objects of the same properties when describing the embodiments of the present application. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, so that a process, method, system, product or device that includes a series of units is not necessarily limited to those units, but may include other units that are not clearly listed or inherent to these processes, methods, products or devices.

[0066] In the description of this application, unless otherwise specified, " / " means or, for example, A / B can mean A or B; "and / or" in this application is merely a description of the association relationship of associated objects, indicating that there can be three relationships, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of this application, "at least one" refers to one or more items, and "multiple items" refers to two or more items. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b, or c can mean: a, b, c, ab, ac, bc, or abc, where a, b, c can be single or multiple.

[0067] The technical solutions provided in the embodiments of the present application can be applied to various communication systems, such as: Global System of Mobile communication (GSM) system, Code Division Multiple Access (CDMA) system, Wideband Code Division Multiple Access (WCDMA) system, General Packet Radio Service (GPRS), Long Term Evolution (LTE) system, LTE frequency division duplex (FDD) system, LTE time division duplex (TDD) system, Universal Mobile Telecommunications System (UMTS), Worldwide Interoperability for Microwave Access (WiMAX) communication system, Fifth Generation (5G) mobile communication system or new radio (NR), wireless local area network (WLAN) system, wireless fidelity (WiFi) system. Among them, the 5G mobile communication system can be a non-standalone (NSA) or standalone (SA) network.

[0068] The technical solution provided in this application can also be applied to machine type communication (MTC), long term evolution-machine (LTE-M), device-to-device (D2D) network, machine-to-machine (M2M) network, Internet of Things (IoT) network or other networks. Among them, the IoT network can include, for example, the Internet of Vehicles. Among them, the communication mode in the Internet of Vehicles system is collectively referred to as vehicle to other devices (vehicle to X, V2X, X can represent anything), for example, the V2X can include: vehicle to vehicle (V2V) communication, vehicle to infrastructure (V2I) communication, vehicle to pedestrian (V2P) communication or vehicle to network (V2N) communication, etc.

[0069] The technical solutions provided in this application can also be applied to future communication systems, such as the sixth generation (6G) mobile communication system. This application does not limit this. In addition, the term "system" can be used interchangeably with "network".

[0070] The network elements involved in this application include network devices and terminal devices. The methods provided in the embodiments of this application can be implemented by program codes in a memory, wherein the methods applied to the network device side can be run in a processing chip within the network device or any device with communication, computing, or storage functions, or in any processing device installed on the network device side; the methods applied to the terminal device side can be run in a built-in processing chip of the terminal device or any device with communication, computing, or storage functions.

[0071] Among them, the network device involved in this application may be a device in a wireless network. For example, the network device may be a device deployed in a radio access network to provide wireless communication functions for terminal devices. For example, the network device may be a radio access network (RAN) node that connects the terminal device to the wireless network, and may also be referred to as an access network device. In the embodiment of the present application, the device for implementing the function of the network device may be a network device; it may be a module or unit that can be applied to the network device; or it may be a device that can support the network device to implement the function, such as a chip system, which can be installed in the network device or used in combination with the network device.

[0072] The network device includes, but is not limited to, an evolved Node B (eNB), a radio network controller (RNC), a Node B (NB), a base station controller (BSC), a base transceiver station (BTS), a home base station (e.g., a home evolved NodeB or home Node B, HNB), a baseband unit (BBU), an access point (AP) in a wireless fidelity (WIFI) system, a wireless relay node, a wireless backhaul node, a transmission point (TP), or a transmission and reception point (TRP), and may also be a network device in a 5G mobile communication system. For example, a next generation NodeB (gNB) in an NR system, a transmission reception point (TRP), or a TP; or one or a group of antenna panels (including multiple antenna panels) of a base station in a 5G mobile communication system; or the network device may also be a network node constituting a gNB or a transmission point. For example, BBU, or distributed unit (DU), etc.

[0073] In some deployments, a gNB may include a centralized unit (CU) and a DU. The gNB may also include an active antenna unit (AAU). The CU implements some gNB functions, while the DU implements some gNB functions. For example, the CU is responsible for processing non-real-time protocols and services, implementing the functions of the radio resource control (RRC) and packet data convergence protocol (PDCP) layers. The DU is responsible for processing physical layer protocols and real-time services, implementing the functions of the radio link control (RLC), MAC, and physical (PHY) layers. The AAU implements some physical layer processing functions, RF processing, and active antenna-related functions. RRC layer information ultimately becomes PHY layer information, or is converted from PHY layer information. Therefore, in this architecture, higher-layer signaling (such as RRC layer signaling) can also be considered to be sent by the DU, or by both the DU and the AAU. It is understood that a network device can be a device including one or more of a CU node, a DU node, and an AAU node. In addition, the CU may be divided into a network device in the RAN, or may be divided into a network device in the core network (CN), which is not limited in this application.

[0074] The terminal device involved in this application may be a wireless terminal device capable of receiving network device scheduling and instruction information. The terminal device may be a device that provides voice and / or data connectivity to a user, or a handheld device with wireless connection function, or other processing device connected to a wireless modem. In the embodiments of this application, the device for implementing the function of the terminal device may be a terminal device; may be a module or unit that can be applied to the terminal device; or may be a device that can support the terminal device to implement the function, such as a chip system, which can be installed in the terminal device or used in combination with the terminal device.

[0075] Terminal devices, also known as user equipment (UE), mobile stations (MS), and mobile terminals (MT), are devices that include wireless communication capabilities (providing voice / data connectivity to users). For example, they include handheld devices or vehicle-mounted devices with wireless connectivity. Currently, some examples of terminal devices include: mobile phones, tablets, laptops, PDAs, mobile internet devices (MIDs), wearable devices, virtual reality (VR) devices, augmented reality (AR) devices, wireless terminals in industrial control, wireless terminals in the Internet of Vehicles (IoV), wireless terminals in self-driving systems, wireless terminals in remote medical surgery, wireless terminals in smart grids, wireless terminals in transportation safety, wireless terminals in smart cities, and wireless terminals in smart homes. For example, wireless terminals in the IoV can be vehicle-mounted devices, complete vehicle equipment, vehicle-mounted modules, vehicles, etc. Wireless terminals in industrial control can be cameras, robots, etc. Wireless terminals in smart homes can be TVs, air conditioners, sweepers, speakers, set-top boxes, etc.

[0076] Figure 1 is a schematic diagram of the architecture of a communication system 100 applicable to an embodiment of the present application. As shown in Figure 1, the communication system 100 may include at least one network device, such as the network device 110 shown in Figure 1; the communication system 100 may also include at least one terminal device, such as the terminal device 120 shown in Figure 1. The network device 110 and the terminal device 120 can communicate via a wireless link. Each communication device, such as the network device 110 or the terminal device 120, can be configured with multiple antennas. For each communication device in the communication system, the configured multiple antennas may include at least one transmitting antenna for sending signals and at least one receiving antenna for receiving signals. Therefore, communication between the communication devices in the communication system and between the network device 110 and the terminal device 120 can be achieved through multi-antenna technology.

[0077] It should be understood that FIG1 is only a simplified schematic diagram for ease of understanding, and the communication system may further include other network devices or other terminal devices, which are not shown in FIG1 .

[0078] It should also be understood that the communication system 100 shown in Figure 1 is only an example of an application scenario of an embodiment of the present application. The present application can also be applied to communication between any two devices, for example, communication between terminal devices, and communication between network devices.

[0079] The ultimate goal of communications security is perfect security, which can be achieved through a one-time pad security scheme. This scheme requires that the length of the random bit sequence be the same as the length of the information bit sequence to be encrypted. In this scheme, the information bit sequence to be encrypted and the random bit sequence are subjected to a bit-by-bit XOR. The random bit sequence must consist of truly random symbols and be used only once. While a one-time pad security scheme is theoretically provably unbreakable, it is extremely expensive to implement.

[0080] Currently, there are no performance indicators that can provide a unified performance evaluation for various secure communication solutions, nor is there a recognized evaluation method to evaluate the gap between the security that can be achieved by different secure communication solutions and the security that can be achieved by one-time pad security solutions.

[0081] Based on this, the present application provides two new general performance indicators for evaluating various types of secure communication solutions, namely the first approximation and the second approximation.

[0082] The first approximation, also known as the one-time pad approximation, can be described as the approximation of the security of the current secure communication scheme to the security of the one-time pad security scheme, or the gap between the security of the current secure communication scheme and the security of the one-time pad security scheme.

[0083] Exemplarily, the first approximation is a ratio of the key entropy required to encrypt the information entropy to the information entropy.

[0084] The calculation method of the first approximation is shown in formula (1):

[0085]

[0086] The specific calculation process is as follows:

[0087] Step A: Generate a random bit sequence and calculate the key entropy based on the length of the random bit sequence.

[0088] Among them, the random bit sequence can be distributed by the upper layer of the network. For example, the random bit sequence can be distributed based on the root key. Alternatively, the random bit sequence can also be generated based on the randomness extracted from the channel or hardware device, as shown in Figures 2A and 2B. Alternatively, the random bit sequence can also be generated by using the BER introduced at the non-target receiving end using physical layer security technology. It is understood that this application does not limit the algorithm used to generate the random bit sequence. It should be noted that in this application, the algorithm used to generate the random bit sequence can also be called a key generation algorithm.

[0089] Furthermore, the minimum entropy H of each bit in the random bit sequence can be evaluated using the National Institute of Standards and Technology (NIST) SP800-90B or other methods. K , the length of the random bit sequence and H K The key entropy E can be obtained by multiplying K .

[0090] Step B: Calculate the information entropy E based on the distribution of the symbols sent by the source in the communication system and the length of the information bit sequence M .

[0091] The distribution of symbols sent by the source affects the information entropy of the generated information bit sequence. For example, if the source generates a symbol with two possible values, 0 and 1, and the probability of generating 0 and 1 is equal, then the entropy of the binary symbol generated by the source is 1 bit / symbol. However, if the probability of generating 0 and 1 is unequal, then the entropy of the binary symbol generated by the source is less than 1 bit / symbol.

[0092] Step C: Calculate the first approximation degree according to formula (1).

[0093] According to the above formula (1), it can be seen that the first approximation has the following properties:

[0094] (1) The reciprocal of the first degree of approximation represents the information entropy that can be protected by each bit of key entropy, or the number of information bits that can be protected by each bit of key entropy.

[0095] (2) It should be noted that the security of a security algorithm or security solution depends on two aspects: one is the complexity of the algorithm, and the other is the freshness of the key, which can be measured by the frequency of key updates.

[0096] For example, for high-level encryption algorithms, if the root key remains unchanged for a long time, the key freshness is low. For example, if the root key is updated daily, the same root key is used every day, resulting in low key freshness. The security of high-level encryption algorithms depends entirely on the algorithm's complexity. For high-level encryption algorithms, the first approximation is close to 0. The root key refers to the key stored in the terminal device's Universal Subscriber Identity Module (USIM) card when the terminal device registers before accessing the network.

[0097] For example, in a one-time pad security scheme, because the random bit sequence and the information bit sequence are updated synchronously, each bit in the random bit sequence is used only once, resulting in the highest key freshness. The encryption algorithm for a one-time pad security scheme is relatively simple, namely, bit-by-bit XOR. Therefore, the security of a one-time pad security scheme depends on the freshness of the key. For a one-time pad security scheme, the first approximation degree is 1.

[0098] (3) The first approximation is also a measure of the security strength of the communication system. The higher the first approximation, the higher the security strength. Regarding formula (1), on the one hand, for a given denominator, a higher first approximation means a greater key entropy, and thus more difficult to crack the key; on the other hand, for a given numerator, a higher first approximation means less information entropy protected by each bit of key entropy, and thus less information leaked due to key theft.

[0099] The second approximation can also be called one-time-one-secret synchronization approximation.

[0100] Exemplarily, the second approximation degree is a ratio of key entropy extracted per unit time to information entropy transmitted per unit time.

[0101] The calculation method of the second approximation is shown in formula (2).

[0102]

[0103] The specific calculation process is as follows:

[0104] Step a: Generate a random bit sequence and calculate the key entropy extracted per unit time based on the generation rate of the random bit sequence.

[0105] Among them, the generation process of random bit sequence and the minimum entropy per bit H K Please refer to the relevant description in the above step A. Further, the generation rate of the random bit sequence is related to H K The key entropy R extracted per unit time can be obtained by multiplying K , the key entropy R extracted per unit time KIt can also be called the generation rate of key entropy.

[0106] The generation rate of the random bit sequence is related to the algorithm used to generate the random bit sequence (ie, the key generation algorithm). For details, please refer to the relevant descriptions of FIG. 2A and FIG. 2B below.

[0107] Step b: By measuring or estimating the information entropy R transmitted per unit time M The information entropy transmitted per unit time can also be called the information transmission rate, or the information bit sequence transmission rate.

[0108] Step c: Calculate the second approximation according to formula (2).

[0109] According to the above formula (2), it can be known that the second approximation has the following properties:

[0110] (1) The second approximation is a measure of the ability to approximate a one-time pad security scheme. Given a given information transmission rate, a higher first approximation means a higher rate at which the communication system generates key entropy, meaning the communication system has a stronger ability to achieve high security that matches the information transmission rate.

[0111] (2) The second degree of approximation can also be used to describe the efficiency of the one-time pad security scheme. For a given first degree of approximation (i.e., a given security strength requirement), a higher second degree of approximation means a higher ratio of the information bit sequence transmission time to the key entropy generation time. This indicates that the additional time overhead introduced to achieve the first degree of approximation is less, that is, the required key entropy generation time is shorter.

[0112] Specifically, from formula (2), we can know:

[0113]

[0114] For example, assuming the key entropy contained in a random bit sequence is m1, and the time required to generate the random bit sequence (also known as the key entropy generation time) is t1, then the key entropy generation rate is m1 / t1, the length of the information bit sequence used to encrypt the random bit sequence is m2, the time required to transmit the information bit sequence (also known as the information bit sequence transmission time) is t2, and the information bit sequence transmission rate is m2 / t2, then the second approximation is equal to (m1 / m2)*(t2 / t1). Therefore, when m1 / m2 is given, a higher second approximation means a larger t2 / t1, that is, a larger ratio of the information bit sequence transmission time to the key entropy generation time. Where m1 is less than or equal to m2.

[0115] The following describes how to calculate the second approximation in an explicit encryption security scheme. An explicit encryption security scheme involves first generating a random bit sequence using wireless environment and / or device characteristics, and then encrypting the plaintext using a one-time pad encryption algorithm or a symmetric encryption algorithm (such as the Advanced Encryption Standard (AES)). For example, the algorithms used to generate the random bit sequence in the explicit encryption security scheme may include a key generation algorithm based on channel reciprocity and a key generation algorithm based on noise entropy (or terminal entropy).

[0116] Figure 2A is a schematic diagram of a key generation algorithm based on channel reciprocity. The key generation algorithm shown in Figure 2A includes four main steps: channel measurement, quantization, information reconciliation, and privacy amplification. First, the communicating parties (e.g., the UE and the gNB) can perform channel measurement by sending channel sounding packets to each other to obtain channel state information (CSI). Next, a quantization algorithm converts the CSI into a binary bit sequence. Due to imperfect channel reciprocity in practice and the inevitable influence of channel estimation errors, the bit sequences generated by the two parties will differ to a certain extent. Therefore, information reconciliation is required to correct any inconsistencies in the bit sequences. This step requires interaction between the communicating parties and carries the risk of information leakage. For example, the communicating parties can send information reconciliation packets to each other. Privacy amplification reduces the amount of leaked information through entropy compression, ensuring that the resulting key bits meet privacy requirements.

[0117] Figure 2B is a schematic diagram of a key generation algorithm based on noise entropy (or terminal entropy). In the key generation algorithm shown in Figure 2B, two communicating parties (e.g., a UE and a gNB) exchange local noise entropy bidirectional security exchange packets. Specifically, the UE transmits its local noise entropy to the gNB, and the gNB transmits its local noise entropy to the UE, so that the UE obtains both the UE's and the gNB's local noise entropies, and the gNB obtains both the UE's and the gNB's local noise entropies. Furthermore, the UE and the gNB exchange error indication field packets. The error indication field packets sent by the UE to the gNB indicate transmission errors in the local noise entropy sent by the gNB, and the error indication field packets sent by the gNB to the UE indicate transmission errors in the local noise entropy sent by the UE. The UE generates a random bit sequence based on the content of the gNB's local noise entropy, excluding the gNB's transmission errors, and the content of the UE's local noise entropy, excluding the UE's transmission errors. The gNB generates a random bit sequence based on the content of the gNB's local noise entropy, excluding the gNB's transmission errors, and the content of the UE's local noise entropy, excluding the UE's transmission errors.

[0118] It will be understood that the above two key generation algorithms are merely examples and are not intended to limit the present application.

[0119] In a possible implementation, under an explicit encryption security scheme, the following description is made by taking the calculation of the second approximation by the first device as an example. The second device can calculate the second approximation with reference to the above content, which will not be repeated here.

[0120] Step 1: The first device sends a first message to the second device, where the first message is used to instruct the first device to start key generation.

[0121] In addition, the second device also sends a second message to the first device, where the second message is used to instruct the second device to start key generation.

[0122] For example, the startup key generation process may be specifically referred to in Figures 2A and 2B . The order in which the first device and the second device initiate the startup key generation is not limited.

[0123] Step 2: The first device sends information related to the first device and used to generate a random bit sequence to the second device; and receives information related to the second device and used to generate a random bit sequence from the second device.

[0124] The information related to the first device and used to generate the random bit sequence may include multiple pieces of information, which may be sent separately or together. In the following FIG2A and FIG2B , the multiple pieces of information are sent separately.

[0125] For example, using FIG2A as an example, assuming that the first device is a UE and the second device is a gNB, the information related to the first device for generating a random bit sequence may include a channel sounding packet sent by the UE to the gNB and an information reconciliation packet sent by the UE to the gNB. The information related to the second device for generating a random bit sequence may include a channel sounding packet sent by the gNB to the UE and an information reconciliation packet sent by the gNB to the UE.

[0126] Taking Figure 2B as an example, assuming the first device is a UE and the second device is a gNB, the information related to the first device used to generate the random bit sequence may include the UE's local noise entropy and a data packet containing a mutual error indication field sent by the UE to the gNB. The information related to the second device used to generate the random bit sequence may include the gNB's local noise entropy and a data packet containing a mutual error indication field sent by the gNB to the UE.

[0127] Step 3: The first device generates a random bit sequence according to the information related to the first device for generating a random bit sequence and the information related to the second device for generating a random bit sequence.

[0128] For example, please refer to the quantization and privacy amplification in FIG2A and the global key generation in FIG2B .

[0129] Step 4: The first device sends a third message to the second device, where the third message is used to indicate that key generation of the first device is complete.

[0130] In addition, the second device also sends a fourth message to the first device, where the fourth message is used to indicate that key generation of the second device is completed.

[0131] For example, the key generation completion process in Figures 2A and 2B may be specifically referred to. The order in which the key generation of the first device and the second device is completed is not limited here.

[0132] Step 5: The first device determines a generation rate of the random bit sequence based on the length of the random bit sequence and a first duration; wherein the first duration is a total duration required to generate the random bit sequence, and the first duration is determined based on the sending time of the first message and the sending time of the third message.

[0133] Among them, the generation rate of random bit sequence r K It is equal to the length of the random bit sequence divided by the first time length T, wherein the specific calculation method of the first time length T is related to the key generation algorithm. Exemplarily, the first time length T is the duration of the entire random bit sequence generation process.

[0134] Taking Figures 2A and 2B as an example, the first duration T starts at the initiation of key generation, and ends at the completion of key generation. Specifically, the timing start time is the time when the party initiating key generation sends a message to the other party instructing the initiation of key generation. After key generation is completed, the timing end time is the time when the party initiating key generation sends a message to the other party instructing the completion of key generation.

[0135] Taking Figure 2A as an example, the first duration T primarily includes the transmission time of the channel sounding packets used for key generation and the transmission time of the information reconciliation packets. The channel sounding packets used for key generation refer to packets sent in addition to the channel sounding packets used for normal channel estimation in the communication system, specifically for key generation. It should be noted that the transmission time of the channel sounding packets used for normal channel estimation must be deducted when calculating T.

[0136] Taking FIG. 2B as an example, the first duration T mainly includes the transmission time of the local noise entropy bidirectional security interaction data packet and the transmission time of the interaction error indication field data packet.

[0137] Step 6: The first device calculates the key entropy extracted per unit time according to the generation rate of the random bit sequence.

[0138] For example, the minimum entropy H of each bit in the random bit sequence can be evaluated using NIST SP800-90B or other methods. K , the random bit sequence generation rate r K With H K The key entropy R extracted per unit time can be obtained by multiplying K .

[0139] Step 8: The first device determines the information entropy transmitted per unit time;

[0140] For example, by measuring or estimating the information entropy R transmitted per unit time M .

[0141] Step 9: The first device determines a second approximation degree according to the key entropy extracted per unit time and the information entropy transmitted per unit time.

[0142] Exemplarily, the second approximation is calculated according to formula (2):

[0143] This compares to existing key generation algorithm evaluation metrics based on the random bit sequence generation rate. However, this metric fails to consider the data transmission requirements of actual communication systems. Therefore, the random bit sequence generation rate is not very meaningful. For example, for system A, assuming the random bit sequence generation rate is 1 Mbps and the information entropy transmitted per unit time is also 1 Mbps, the system can achieve a one-time pad that matches the information entropy transmitted per unit time. However, for system B, assuming the random bit sequence rate is also 1 Mbps but the information entropy transmitted per unit time is 1 Gbps, the system cannot achieve a one-time pad that matches the information entropy transmitted per unit time. Therefore, the second approximation, which considers both the random bit sequence generation rate and the information entropy transmitted per unit time, provides a more valuable and instructive evaluation of key generation algorithms.

[0144] From the above, it can be seen that this application proposes a general indicator measurement for evaluating various types of security communication schemes, namely the first approximation and the second approximation, which can measure the security performance of different security communication schemes and make a unified performance evaluation. In addition, it can also evaluate the gap between the security that can be achieved by different security communication schemes and the security that can be achieved by the one-time pad security scheme.

[0145] Furthermore, based on the general indicator measurement for evaluating various types of secure communication solutions proposed in this application, this application provides a data transmission method. In the following method, the first device may be a network device, the second device may be a terminal device, or the first device may be a terminal device, and the second device may be a network device. In this method, the method is applicable to but not limited to the communication system architecture of Figure 1, and the method may be executed by the transceiver and / or processor of the terminal device (which may also be a network device), or by the chip corresponding to the transceiver and / or processor. Alternatively, this embodiment may also be implemented by a controller or control device to which the terminal device (which may also be a network device) is connected, and the controller or control device is used to manage at least one device including the terminal device (which may also be a network device). In addition, this application does not specifically limit the specific form of the communication device that executes this embodiment.

[0146] FIG3 shows a data transmission method, which includes:

[0147] S300: The first device generates a first random bit sequence and determines a total amount of key entropy according to the length of the first random bit sequence.

[0148] Exemplarily, the first device may use any one of the two key generation algorithms shown in FIG. 2A and FIG. 2B to generate the first random bit sequence. In addition, the first device may also use other key generation algorithms to generate the first random bit sequence, which is not limited in this application.

[0149] Furthermore, before S300 , before the first device generates the first random bit sequence, the first device may determine with the second device at least one of a first approximation degree, a key generation algorithm, and a width of a key generation time window.

[0150] The definition of the first degree of approximation can be referred to the above-mentioned related description and will not be repeated here. The key generation algorithm can be any of the two key generation algorithms shown in Figures 2A and 2B above, or other key generation algorithms, which are not limited in this application. The width of the key generation time window refers to the duration of generating the random bit sequence.

[0151] In one possible implementation, the first device and the second device may configure a list of first approximations, wherein the list of first approximations includes a plurality of values ​​of the first approximation. For example, the first device may send a first value of the first approximation to the second device. If the second device can satisfy that the first approximation is the first value, a notification message may be sent to the second device, where the notification message is used to indicate that the second device agrees that the first approximation is the first value. If the second device cannot satisfy that the first approximation is the first value, a second value of the first approximation may be sent to the second device, where the second value is lower than the first value. If the first device can satisfy that the first approximation is the second value, a notification message may be sent to the first device, where the notification message is used to indicate that the first device agrees that the first approximation is the second value.

[0152] In addition, the first device and the second device may configure a list of key generation algorithms and / or a list of key generation time window widths, and determine the key generation algorithm and the key generation time window width in a similar manner to the above.

[0153] In another possible implementation, the first device and the second device may configure a list of correspondences between at least two parameters among the first approximation degree, the key generation algorithm, and the width of the key generation time window, and determine the first approximation degree, the key generation algorithm, and the width of the key generation time window in a manner similar to the above.

[0154] S310. The first device determines the key entropy N required to encrypt the information entropy based on the information entropy of the first information bit sequence and the first approximation, wherein the first approximation is the ratio of the key entropy required to encrypt the information entropy to the information entropy, and N is a positive integer.

[0155] Exemplarily, the first device may divide all information bits to be sent into at least one information bit group to be sent, or also referred to as at least one data group, or at least one data group to be sent, wherein each information bit group includes an information bit sequence, and an information bit sequence includes at least one information bit.

[0156] Among them, the first information bit group in at least one information bit group to be sent includes a first information bit sequence, or is described as, the first information bit group is composed of the first information bit sequence, and the first information bit group is any one of the at least one information bit group to be sent.

[0157] In one possible implementation, if the first device is a network device and the second device is a terminal device, the network device can determine at least one information bit group to be sent and the information entropy of each information bit group based on the time-frequency resources and modulation and coding scheme (MCS) allocated to the terminal device, wherein the first information bit sequence constitutes any one of the at least one information bit group to be sent.

[0158] Since the first approximation is the ratio of the key entropy required to encrypt the information entropy to the information entropy, the first approximation can be expressed as the ratio of the information entropy of the first information bit sequence to the key entropy required to encrypt the information entropy. Furthermore, when the first device obtains the information entropy of the first information bit sequence and the first approximation, the first device can multiply the two to obtain the key entropy required to encrypt the information entropy. That is, assuming the first approximation is D0 and the information entropy of the first information bit sequence is M bits, then the key entropy required to encrypt the information entropy is N bits, where N = D0 * M. M is a positive integer, and D0 is greater than zero.

[0159] S320. When the key entropy N required to encrypt the information entropy is less than or equal to the total key entropy, the first device encrypts the information entropy of the first information bit sequence based on N bits in the total key entropy to obtain a ciphertext.

[0160] The ciphertext is the encrypted first information bit sequence, that is, the ciphertext here is the ciphertext corresponding to the first information bit sequence.

[0161] Exemplarily, when the key entropy N required to encrypt the information entropy of the first information bit sequence is less than or equal to the total key entropy, the first device can take out any N bits from the total key entropy, or take out N bits from the total key entropy according to a preset order. This application does not limit the specific method in which the first device determines N bits from the total key entropy.

[0162] Furthermore, when the first device encrypts the information entropy of the first information bit sequence based on N bits in the total key entropy to obtain the ciphertext, the first device may obtain the ciphertext in the following manner, but not limited to:

[0163] Method 1: The first device generates a key stream using a preset encryption algorithm based on the N bits and the encryption key. It then performs an XOR operation on the key stream and the information entropy of the first information bit sequence to obtain ciphertext. The encryption key is determined based on the root key. For example, the encryption key is derived layer by layer from the root key. This is shown in Figure 4A.

[0164] Method 2: The first device generates a key stream using a preset encryption algorithm based on N bits and preset parameters, and XORs the key stream with the information entropy of the first information bit sequence to obtain a ciphertext, as shown in FIG4B .

[0165] The preset parameters may refer to parameters that change regularly, such as a packet data convergence protocol (PDCP) packet counter, a key stream length, a bearer identifier, an uplink or downlink direction, and the like.

[0166] For the above-mentioned method 1 and method 2, the number of bits included in the key stream is the same as the number of bits included in the information entropy of the first information bit sequence.

[0167] Method 3: The first device obtains the ciphertext using a preset encryption algorithm according to the N bits and the information entropy of the first information bit sequence, as shown in FIG4C .

[0168] For the above-mentioned methods 1 to 3, the preset encryption algorithm is a symmetric encryption algorithm or other encryption algorithm, which is not limited in this application.

[0169] In addition, when the key entropy N required for encrypting the information entropy is greater than the total key entropy, the first device and the second device need to redetermine at least one of the first approximation degree, the key generation algorithm or the width of the key generation time window.

[0170] For example, the first device and the second device can reduce the first approximation degree through signaling interaction, so that the key entropy N required for the encrypted information entropy is reduced, thereby making it easier to meet the requirement that the key entropy required for the encrypted information entropy is less than the total key entropy.

[0171] For another example, the first device and the second device can replace the key generation algorithm through signaling interaction, so that the total amount of key entropy generated by the replaced key generation algorithm increases, thereby making it easier to meet the key entropy required for the encrypted information entropy to be less than the total amount of key entropy.

[0172] For another example, the first device and the second device can increase the width of the key generation time window through signaling interaction, so that the length of the generated random bit sequence increases, thereby increasing the total amount of key entropy, making it easier to meet the requirement that the key entropy required for the encrypted information entropy is less than the total amount of key entropy.

[0173] Therefore, by re-determining at least one of the above three parameters, it is possible to achieve that the key entropy required for encrypting the information entropy is less than the total key entropy.

[0174] In one possible implementation, when it is necessary to encrypt information entropy corresponding to multiple information bit groups to be sent, that is, the first information bit sequence constitutes any one of the multiple information bit groups to be sent, after obtaining the ciphertext corresponding to the first information bit sequence (that is, after S320), the first device needs to further perform the following judgment:

[0175] (1) Whether there are other unencrypted information bit groups;

[0176] (2) If there are other unencrypted information bit groups, is the remaining key entropy in the total key entropy greater than or equal to N bits? It is understood that each information bit group includes the same number of bits, that is, the information entropy of each information bit group is the same. Therefore, for the same first degree of approximation, the key entropy required to encrypt each information bit group is the same.

[0177] When there is an unencrypted information bit group and the remaining key entropy in the total key entropy is greater than or equal to N bits, the first device encrypts the information entropy of the unencrypted information bit group based on N bits of the remaining key entropy in the total key entropy until the encryption of all information bit groups is completed.

[0178] When there is an unencrypted information bit group and the remaining key entropy in the total key entropy is less than N bits, the first device generates a second random bit sequence.

[0179] The remaining key entropy in the total key entropy being less than N bits may include a situation where the remaining key entropy in the total key entropy is 0 bits (ie, all the key entropy is used up).

[0180] The second random bit sequence is a new random bit sequence that is different from the first random bit sequence. The key generation algorithm used to generate the second random bit sequence may be the same as or different from the key generation algorithm used to generate the first random bit sequence, and this application does not limit this. For example, the first device and the second device may re-determine a time duration and, based on the time duration, use the same key generation algorithm used to generate the first random bit sequence to generate the second random bit sequence.

[0181] Furthermore, after completing the generation of the second random bit sequence, the first device can determine the total amount of key entropy corresponding to the second bit sequence based on the length of the second random bit sequence. When the key entropy N required to encrypt the information entropy corresponding to an unencrypted information bit group is less than or equal to the total amount of key entropy corresponding to the second bit sequence, the first device encrypts the information entropy corresponding to the unencrypted information bit group based on N bits in the total amount of key entropy corresponding to the second bit sequence to obtain the corresponding ciphertext.

[0182] If there are other unencrypted information bit groups and the remaining key entropy in the total key entropy corresponding to the second bit sequence is less than N bits, the first device generates a third random bit sequence and repeats the above process until all information bit groups are encrypted.

[0183] S330: The first device sends a ciphertext to the second device.

[0184] By adopting the above method, the first approximation degree is introduced into the communication system as a universal indicator measurement of the secure communication scheme, and data transmission that meets specific security performance can be achieved through the above process.

[0185] FIG5 shows another data transmission method, which includes:

[0186] S500: The first device generates a random bit sequence in a first time period, and determines a total amount of key entropy according to the length of the random bit sequence.

[0187] Exemplarily, the first device may use any one of the two key generation algorithms shown in FIG. 2A and FIG. 2B to generate a random bit sequence. In addition, the first device may also use other key generation algorithms to generate a random bit sequence, which is not limited in this application.

[0188] In one possible design, before the first device generates the random bit sequence, that is, before S500 , the first device and the second device determine at least one of a first approximation, a second approximation, a key generation algorithm, and a key update period.

[0189] S510: The first device determines the information entropy that needs to be transmitted within the second time period according to the first approximation degree and the total key entropy.

[0190] The first duration and the second duration are both determined based on the first approximation, the second approximation, and the key update period, wherein the sum of the first duration and the second duration is the key update period. The definitions of the first approximation and the second approximation can be referred to the above related description and will not be repeated here.

[0191] In a possible design, in the frame structure shown in FIG6 , the first duration = αT, the second duration = (1-α)T, N represents key entropy, M represents information entropy, and T represents the key update period.

[0192] According to the definition of first approximation:

[0193]

[0194] According to the definition of the second approximation:

[0195]

[0196] Wherein, D0 represents the first approximation, d0 represents the second approximation, N / (αT) represents the key entropy extracted per unit time, and M / (1-α)T represents the information entropy transmitted per unit time.

[0197] According to the above formula (3) and formula (4), we can get:

[0198] We can further know that

[0199] It can be understood that since the information entropy that needs to be transmitted is determined based on the total key entropy and the first approximation degree, the key entropy required to encrypt the information entropy that needs to be transmitted is the total key entropy. Therefore, there will be no situation where the information entropy that needs to be transmitted cannot be encrypted due to insufficient total key entropy.

[0200] Furthermore, for the first duration and the second duration determined using the above method, the total amount of key entropy obtained for the first durations in different frames can be the same or different. When the total amount of key entropy obtained for the first durations in different frames is different, the information entropy required to be transmitted determined based on the first degree of approximation is also different. Alternatively, the number of information bits transmitted for the second durations in different frames can be the same or different.

[0201] S520. The first device encrypts the information entropy to be transmitted according to the total amount of key entropy to obtain a ciphertext.

[0202] S520 can refer to the three encryption methods in S320, which will not be repeated here.

[0203] S530: The first device sends a ciphertext to the second device.

[0204] By adopting the above method, the first approximation degree and the second approximation degree are introduced into the communication system as universal indicator measurements of the secure communication scheme. Through the above process, data transmission can be achieved under the premise of given security performance requirements and system security capabilities.

[0205] Figure 7 shows a possible exemplary block diagram of a communication device involved in an embodiment of the present application. The device 700 includes a transceiver module 720 and a processing module 710. The transceiver module 720 may include a receiving unit and a sending unit. The processing module 710 is used to control and manage the operation of the device 700. The transceiver module 720 is used to support communication between the device 700 and other network entities. Optionally, the device 700 may also include a storage unit for storing program code and data of the device 700.

[0206] Optionally, each module in the apparatus 700 may be implemented by software.

[0207] Optionally, the processing module 710 can be a processor or a controller, for example, a general-purpose central processing unit (CPU), a general-purpose processor, a digital signal processing (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, a transistor logic device, a hardware component or any combination thereof. It can implement or execute the various exemplary logic blocks, modules and circuits described in conjunction with the disclosure of the embodiments of the present application. The processor can also be a combination that implements a computing function, for example, a combination of one or more microprocessors, a combination of a DSP and a microprocessor, and the like. The transceiver module 720 can be a communication interface, a transceiver or a transceiver circuit, etc., wherein the communication interface is a general term. In a specific implementation, the communication interface can include multiple interfaces, and the storage unit can be a memory.

[0208] When the apparatus 700 is a first device or a chip in the first device, the processing module 710 in the apparatus 700 can support the apparatus 700 in executing the actions of the first device in each method example above, for example, it can support the apparatus 700 in executing S300, S310, S320 in FIG. 3 , or S500, S510, S520 in FIG. 5 .

[0209] The transceiver module 720 may support the apparatus 700 to communicate with the second device. For example, the transceiver module 720 may support the apparatus 700 to execute S330 in FIG. 3 or S530 in FIG. 5 .

[0210] For example, the processing module 710 is configured to generate a first random bit sequence and determine a total key entropy based on the length of the first random bit sequence; determine a key entropy N required to encrypt the information entropy based on the information entropy of the first information bit sequence and a first approximation, wherein the first approximation is a ratio of the key entropy required to encrypt the information entropy to the information entropy, and N is a positive integer; if the key entropy N required to encrypt the information entropy is less than or equal to the total key entropy, encrypt the information entropy based on N bits in the total key entropy to obtain a ciphertext;

[0211] The transceiver module 720 is configured to send the ciphertext to the second device.

[0212] In one possible design, the processing module 710 is used to encrypt the information entropy based on N bits in the total key entropy to obtain a ciphertext, generate a key stream using a preset encryption algorithm according to the N bits and the encryption key, and XOR the key stream with the information entropy to obtain the ciphertext, where the encryption key is determined based on the root key; or, generate a key stream using a preset encryption algorithm according to the N bits and preset parameters, and XOR the key stream with the information entropy to obtain the ciphertext; or, obtain the ciphertext using a preset encryption algorithm according to the N bits and the information entropy.

[0213] In one possible design, the processing module 710 calls the transceiver module 720 to execute: before generating the first random bit sequence, determine at least one of the first approximation degree, the key generation algorithm, and the width of the key generation time window with the second device.

[0214] In one possible design, the processing module 710 calls the transceiver module 720 to execute: when the key entropy N required to encrypt the information entropy is greater than the total key entropy, redetermine with the second device at least one of the first approximation degree, the key generation algorithm or the width of the key generation time window.

[0215] In one possible design, the first information bit group is composed of the first information bit sequence, and the first information bit group is any one of at least one information bit group to be sent; the processing module 710 is used to generate a second random bit sequence after the first device encrypts the information entropy based on N bits in the total key entropy to obtain a ciphertext, and when the remaining key entropy in the total key entropy is less than N bits and there is an unencrypted information bit group in the at least one information bit group to be sent.

[0216] In one possible design, the first device is a network device and the second device is a terminal device, or the first device is a terminal device and the second device is a network device.

[0217] For another example, the processing module 710 is configured to generate a random bit sequence in a first time duration, and determine a total key entropy based on the length of the random bit sequence, wherein the first time duration is determined based on a first approximation, a second approximation, and a key update period, wherein the first approximation is the ratio of the key entropy required to encrypt the information entropy to the information entropy, and the second approximation is the ratio of the key entropy extracted per unit time to the information entropy transmitted per unit time; determine the information entropy to be transmitted in a second time duration based on the first approximation and the total key entropy, wherein the sum of the first time duration and the second time duration is the key update period; and encrypt the information entropy to be transmitted based on the total key entropy to obtain a ciphertext.

[0218] The transceiver module 720 is configured to send the ciphertext to the second device.

[0219] In one possible design, the described Wherein, T represents the key update period, D0 represents the first approximation degree, and d0 represents the second approximation degree.

[0220] In one possible design, the processing module 710 is used to encrypt the information entropy to be transmitted according to the total key entropy to obtain the ciphertext, generate a key stream using a preset encryption algorithm according to the total key entropy and the encryption key, and XOR the key stream with the information entropy to be transmitted to obtain the ciphertext; or, generate a key stream using a preset encryption algorithm according to the total key entropy and preset parameters, and XOR the key stream with the information entropy to be transmitted to obtain the ciphertext; or, obtain the ciphertext using a preset encryption algorithm according to the total key entropy and preset parameters.

[0221] In one possible design, the processing module 710 calls the transceiver module 720 to execute: before the first device generates a random bit sequence, determine at least one of the first approximation, the second approximation, the key generation algorithm and the key update period with the second device.

[0222] In one possible design, the apparatus is a network device and the second device is a terminal device; alternatively, the apparatus is a terminal device and the second device is a network device.

[0223] It should be understood that the device 700 according to the embodiment of the present application may correspond to the first device in the aforementioned method embodiment, and the operations and / or functions of the various modules in the device 700 are respectively for implementing the corresponding steps of the method of the first device in the aforementioned method embodiment, and therefore the beneficial effects in the aforementioned method embodiment can also be achieved. For the sake of brevity, they are not elaborated here.

[0224] FIG8 shows a schematic structural diagram of a communication device 800 according to an embodiment of the present application. As shown in FIG8 , the device 800 includes: a processor 801 .

[0225] When the apparatus 800 is a first device or a chip in the first device, in one possible implementation, the processor 801 is used to call an interface to perform the following actions: generate a first random bit sequence, and determine the total amount of key entropy based on the length of the first random bit sequence; determine the key entropy N required to encrypt the information entropy based on the information entropy and the first approximation of the first information bit sequence, wherein the first approximation is the ratio of the key entropy required to encrypt the information entropy to the information entropy, and N is a positive integer; when the key entropy N required to encrypt the information entropy is less than or equal to the total amount of key entropy, encrypt the information entropy based on N bits in the total amount of key entropy to obtain a ciphertext; and send the ciphertext to the second device.

[0226] In another possible implementation, when the processor 801 is used to call the interface to perform the following actions: generate a random bit sequence in a first time length, and determine the total amount of key entropy based on the length of the random bit sequence, wherein the first time length is determined based on a first approximation, a second approximation and a key update period, the first approximation is the ratio of the key entropy required for encrypting information entropy to the information entropy, and the second approximation is the ratio of the key entropy extracted per unit time to the information entropy transmitted per unit time; determine the information entropy that needs to be transmitted within a second time length based on the first approximation and the total amount of key entropy, wherein the sum of the first time length and the second time length is the key update period; encrypt the information entropy that needs to be transmitted based on the total amount of key entropy to obtain a ciphertext; and send the ciphertext to the second device.

[0227] It should be understood that the apparatus 800 may also be used to execute other steps and / or operations of the first device in the foregoing embodiment, which are not described here for the sake of brevity.

[0228] It should be understood that the processor 801 can call an interface to perform the above-mentioned sending and receiving actions, wherein the called interface can be a logical interface or a physical interface, which is not limited to this. Optionally, the physical interface can be implemented by a transceiver. Optionally, the device 800 also includes a transceiver 803.

[0229] Optionally, the apparatus 800 further includes a memory 802 , which can store program codes in the above method embodiments for easy calling by the processor 801 .

[0230] Specifically, if the device 800 includes a processor 801, a memory 802, and a transceiver 803, the processor 801, the memory 802, and the transceiver 803 communicate with each other through an internal connection path to transmit control and / or data signals. In one possible design, the processor 801, the memory 802, and the transceiver 803 can be implemented by a chip. The processor 801, the memory 802, and the transceiver 803 can be implemented in the same chip, or they can be implemented in different chips, or any two of their functions can be combined and implemented in a single chip. The memory 802 can store program code, and the processor 801 calls the program code stored in the memory 802 to implement the corresponding functions of the device 800.

[0231] The present application also provides a communication system, which includes a first device and a second device, wherein the first device is used to execute the steps and / or operations on the first device side in the above embodiment, and the second device is used to execute the steps and / or operations on the second device side in the above embodiment.

[0232] The methods disclosed in the above embodiments of the present application can be applied to a processor or implemented by a processor. The processor may be an integrated circuit chip with signal processing capabilities. During implementation, the steps of the above method embodiments can be completed by hardware integrated logic circuits in the processor or instructions in software form. The above processor can be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic device, a discrete hardware component, a system on chip (SoC), a central processing unit (CPU), a network processor (NP), a digital signal processing circuit (DSP), a microcontroller unit (MCU), a programmable logic device (PLD) or other integrated chip. The methods, steps and logic block diagrams disclosed in the embodiments of the present application can be implemented or executed. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor. The steps of the method disclosed in the embodiments of this application can be directly implemented and executed by a hardware decoding processor, or by a combination of hardware and software modules in the decoding processor. The software module can be located in a storage medium well-known in the art, such as random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, etc. The storage medium is located in the memory, and the processor reads the information in the memory and, in conjunction with its hardware, completes the steps of the above method.

[0233] It is understood that the memory in the embodiments of the present application may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM), which is used as an external cache. By way of example and not limitation, many forms of RAM are available, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), and direct RAM bus RAM (DR RAM). It should be noted that the memory of the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0234] An embodiment of the present application further provides a computer-readable storage medium, which stores a computer program. When the computer program runs on a computer, the computer executes the methods shown in the above embodiments.

[0235] The methods provided in the embodiments of the present application can be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented using software, they can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present invention is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, a network device, a user device, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via a wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) method. The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server or data center that includes one or more available media integrated therein. The available medium may be a magnetic medium (eg, a floppy disk, a hard disk, a magnetic tape), an optical medium (eg, a digital video disc (DVD)), or a semiconductor medium (eg, a solid state disk (SSD)).

[0236] The above embodiments are merely a detailed introduction to the technical solutions of the present application. However, the descriptions of the above embodiments are intended only to facilitate understanding of the methods of the embodiments of the present invention and should not be construed as limiting the embodiments of the present invention. Any changes or substitutions that can be readily conceived by those skilled in the art should fall within the scope of protection of the embodiments of the present invention.

Claims

1. A data transmission method, characterized in that: The method includes: The first device generates a first random bit sequence and determines a total amount of key entropy according to a length of the first random bit sequence; The first device determines, based on the information entropy of the first information bit sequence and a first approximation, a key entropy N required to encrypt the information entropy, wherein the first approximation is a ratio of the key entropy required to encrypt the information entropy to the information entropy, and N is a positive integer; When the key entropy N required to encrypt the information entropy is less than or equal to the total key entropy, the first device encrypts the information entropy based on N bits in the total key entropy to obtain a ciphertext; The first device sends the ciphertext to the second device.

2. The method according to claim 1, wherein The first device encrypts the information entropy based on N bits of the total key entropy to obtain a ciphertext, including: The first device generates a key stream using a preset encryption algorithm according to the N bits and an encryption key, and performs an exclusive OR operation on the key stream and the information entropy to obtain the ciphertext, where the encryption key is determined based on a root key; Alternatively, the first device generates a key stream using a preset encryption algorithm according to the N bits and preset parameters, and performs an XOR operation on the key stream and the information entropy to obtain the ciphertext; Alternatively, the first device obtains the ciphertext using a preset encryption algorithm based on the N bits and the information entropy.

3. The method according to claim 1 or 2, wherein: Before the first device generates the first random bit sequence, the method further includes: The first device and the second device determine at least one of the first approximation degree, a key generation algorithm, and a width of a key generation time window.

4. The method according to claim 3, wherein Also includes: When the key entropy N required to encrypt the information entropy is greater than the total key entropy, the first device and the second device redetermine at least one of the first approximation degree, the key generation algorithm or the width of the key generation time window.

5. The method according to any one of claims 1 to 4, characterized in that The first information bit group is composed of the first information bit sequence, and the first information bit group is any one of the at least one information bit group to be sent; After the first device encrypts the information entropy based on N bits of the total key entropy to obtain a ciphertext, the method further includes: In a case where the remaining key entropy in the total key entropy is less than N bits and there is an unencrypted information bit group in the at least one information bit group to be sent, the first device generates a second random bit sequence.

6. The method according to any one of claims 1 to 5, wherein: The first device is a network device, and the second device is a terminal device, or the first device is a terminal device, and the second device is a network device.

7. A data transmission method, characterized in that: The method includes: The first device generates a random bit sequence for a first duration, and determines a total amount of key entropy based on a length of the random bit sequence, wherein the first duration is determined based on a first approximation, a second approximation, and a key update period, the first approximation being a ratio of key entropy required to encrypt information entropy to the information entropy, and the second approximation being a ratio of key entropy extracted per unit time to information entropy transmitted per unit time; The first device determines, according to the first approximation degree and the total key entropy, information entropy that needs to be transmitted within a second duration, wherein the sum of the first duration and the second duration is the key update period; The first device encrypts the information entropy to be transmitted according to the total amount of key entropy to obtain a ciphertext; The first device sends the ciphertext to the second device.

8. The method according to claim 7, wherein described described Wherein, T represents the key update period, D0 represents the first approximation degree, and d0 represents the second approximation degree.

9. The method according to claim 7 or 8, wherein The first device encrypts the information entropy to be transmitted according to the total key entropy to obtain ciphertext, including: The first device generates a key stream using a preset encryption algorithm according to the total key entropy and the encryption key, and performs an exclusive OR operation on the key stream and the information entropy to be transmitted to obtain the ciphertext; Alternatively, the first device generates a key stream using a preset encryption algorithm according to the total amount of key entropy and preset parameters, and performs an XOR operation on the key stream and the information entropy to be transmitted to obtain the ciphertext; Alternatively, the first device obtains the ciphertext using a preset encryption algorithm based on the total amount of key entropy and the information entropy to be transmitted.

10. The method according to any one of claims 7 to 9, characterized in that Before the first device generates the random bit sequence, the method further includes: The first device and the second device determine at least one of the first approximation, the second approximation, a key generation algorithm, and the key update period.

11. The method according to any one of claims 7 to 10, wherein: The first device is a network device, and the second device is a terminal device, or the first device is a terminal device, and the second device is a network device.

12. A data transmission device, characterized in that: The device includes: a processing module and a transceiver module; The processing module is configured to generate a first random bit sequence and determine a total key entropy based on a length of the first random bit sequence; determine a key entropy N required to encrypt the information entropy based on the information entropy of the first information bit sequence and a first approximation, wherein the first approximation is a ratio of the key entropy required to encrypt the information entropy to the information entropy, and N is a positive integer; and if the key entropy N required to encrypt the information entropy is less than or equal to the total key entropy, encrypt the information entropy based on N bits of the total key entropy to obtain a ciphertext; The transceiver module is used to send the ciphertext to the second device.

13. The device according to claim 12, wherein The processing module is used to encrypt the information entropy based on N bits in the total key entropy to obtain a ciphertext, generate a key stream using a preset encryption algorithm according to the N bits and the encryption key, and XOR the key stream with the information entropy to obtain the ciphertext, where the encryption key is determined based on the root key; or, generate a key stream using a preset encryption algorithm according to the N bits and preset parameters, and XOR the key stream with the information entropy to obtain the ciphertext; or, obtain the ciphertext using a preset encryption algorithm according to the N bits and the information entropy.

14. The device according to claim 12 or 13, characterized in that The processing module calls the transceiver module to execute: before generating the first random bit sequence, determining at least one of the first approximation degree, the key generation algorithm and the width of the key generation time window with the second device.

15. The device according to claim 14, wherein The processing module calls the transceiver module to execute: when the key entropy N required to encrypt the information entropy is greater than the total key entropy, redetermine at least one of the first approximation degree, the key generation algorithm or the width of the key generation time window with the second device.

16. The device according to any one of claims 12 to 15, characterized in that The first information bit group is composed of the first information bit sequence, and the first information bit group is any one of the at least one information bit group to be sent; The processing module is used to generate a second random bit sequence after the first device encrypts the information entropy based on N bits in the total key entropy to obtain a ciphertext, if the remaining key entropy in the total key entropy is less than N bits and there is an unencrypted information bit group in the at least one information bit group to be sent.

17. The device according to any one of claims 12 to 16, characterized in that The apparatus is a network device, and the second device is a terminal device; or the apparatus is a terminal device, and the second device is a network device.

18. A data transmission device, characterized in that: The device includes: a processing module and a transceiver module; The processing module is configured to generate a random bit sequence in a first time duration, and determine a total key entropy based on the length of the random bit sequence, wherein the first time duration is determined based on a first approximation, a second approximation, and a key update period, wherein the first approximation is the ratio of the key entropy required to encrypt information entropy to the information entropy, and the second approximation is the ratio of the key entropy extracted per unit time to the information entropy transmitted per unit time; determine the information entropy to be transmitted in a second time duration based on the first approximation and the total key entropy, wherein the sum of the first time duration and the second time duration is the key update period; and encrypt the information entropy to be transmitted based on the total key entropy to obtain a ciphertext; The transceiver module is used to send the ciphertext to the second device.

19. The device according to claim 18, wherein described described Wherein, T represents the key update period, D0 represents the first approximation degree, and d0 represents the second approximation degree.

20. The device according to claim 18 or 19, characterized in that The processing module is used to, when encrypting the information entropy to be transmitted according to the total amount of key entropy to obtain a ciphertext, generate a key stream using a preset encryption algorithm according to the total amount of key entropy and an encryption key, and XOR the key stream with the information entropy to be transmitted to obtain the ciphertext; or, generate a key stream using a preset encryption algorithm according to the total amount of key entropy and preset parameters, and XOR the key stream with the information entropy to be transmitted to obtain the ciphertext; or, obtain the ciphertext using a preset encryption algorithm according to the total amount of key entropy and the information entropy to be transmitted.

21. The device according to any one of claims 18 to 20, characterized in that The processing module calls the transceiver module to execute: determining at least one of the first approximation degree, the second approximation degree, the key generation algorithm and the key update period with the second device before the first device generates a random bit sequence.

22. The device according to any one of claims 18 to 21, characterized in that The apparatus is a network device, and the second device is a terminal device, or the apparatus is a terminal device, and the second device is a network device.

23. A communication device, characterized in that: The method comprises a unit or module for executing the method according to any one of claims 1 to 6, or a unit or module for executing the method according to any one of claims 7 to 11.

24. A communication device, characterized in that: The communication device includes a processor and a storage medium, wherein the storage medium stores instructions. When the instructions are executed by the processor, the method according to any one of claims 1 to 6 is implemented, or the method according to any one of claims 7 to 11 is implemented.

25. A communication device, characterized in that: including a processor and an interface circuit; The interface circuit is configured to receive code instructions and transmit the code instructions to the processor; the processor runs the code instructions to execute the method according to any one of claims 1 to 11.

26. A readable storage medium, characterized in that The readable storage medium is used to store instructions, and when the instructions are executed, the method according to any one of claims 1 to 11 is implemented.

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