Apparatus and method for supporting security in user equipment

Abstract

A method for supporting security in a user equipment (UE) includes generating, by the UE, at least one 256-bit security key for a 5G network in the UE without truncation operations or by removing truncation operations to support 256-bit encryption and integrity protection, and establishing, by the UE, secure communication between the UE and a network device using the at least one 256-bit security key.

Description

Cross-reference to related applications

[0001] This application claims priority to U.S. Provisional Application No. 63 / 605,986, filed December 4, 2023, entitled “METHOD FOR KEY GENERATION AND KEY USAGE INDICATION IN 5G,” which is incorporated herein by reference in its entirety. Technical Field

[0002] This disclosure relates to the field of communication systems, and more specifically, to apparatus and methods for supporting security in user equipment (UE). Background Technology

[0003] Currently, 5G networks only support 128-bit encryption algorithms, while some non-5G networks support both 128-bit and 256-bit algorithms. In 5G, the keys used for cryptographic and integrity algorithms are 128-bit because 256-bit algorithms were not previously supported. In other networks, the application layer typically pre-configures security algorithms and generates corresponding keys (128-bit or 256-bit). These networks often use more powerful equipment, prioritizing functionality over efficiency. Non-5G communication is typically end-to-end, with intermediate nodes unaware of encryption, and does not support mobility or soft handover. Therefore, current solutions lack backward compatibility and interoperability, a challenge unique to mobile networks.

[0004] Therefore, there is a need for apparatus and methods to support security in user equipment (UE). Summary of the Invention

[0005] The purpose of this disclosure is to provide apparatus and methods for supporting security in user equipment (UE) that can maintain backward compatibility and interoperability and / or enhance security.

[0006] In a first aspect of this disclosure, a method for supporting security in a user equipment (UE) includes: generating, by the UE, at least one 256-bit security key for a 5G network without a truncation operation or by removing a truncation operation, to support 256-bit encryption and integrity protection; and establishing secure communication between the UE and a network device using the at least one 256-bit security key.

[0007] In a second aspect of this disclosure, a communication system includes a memory, a transceiver, and a processor coupled to the memory and the transceiver. The processor is configured to perform: generating, in a UE, at least one 256-bit security key for a 5G network, either without a truncation operation or by removing a truncation operation, to support 256-bit encryption and integrity protection; and establishing secure communication between the UE and a network device using the at least one 256-bit security key.

[0008] In a third aspect of this disclosure, a non-transitory machine-readable storage medium stores instructions that, when executed by a computer, cause the computer to perform the methods described above.

[0009] In a fourth aspect of this disclosure, a chip includes a processor configured to invoke and run a computer program stored in a memory to cause a device on which the chip is mounted to perform the methods described above.

[0010] In a fifth aspect of this disclosure, a computer-readable storage medium is provided, wherein a computer program is stored that causes a computer to perform the above-described method.

[0011] In a sixth aspect of this disclosure, a computer-readable storage medium is provided, wherein a computer program is stored that causes a computer to perform the above-described method.

[0012] In a seventh aspect of this disclosure, a computer program product includes a computer program that causes a computer to perform the methods described above.

[0013] In an eighth aspect of this disclosure, a computer program causes a computer to perform the above-described method. Attached Figure Description

[0014] To more clearly illustrate the embodiments or related technologies of this disclosure, the following drawings will be described in the brief introduction of the embodiments. Obviously, the drawings are merely some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings without substantial effort.

[0015] Figure 1 This is a block diagram of a communication system according to an embodiment of the present disclosure.

[0016] Figure 2 This is a flowchart illustrating a method for supporting security in a user equipment (UE) according to an embodiment of the present disclosure.

[0017] Figure 3 This is a schematic diagram illustrating an example of the current key hierarchy and key generation in 5G.

[0018] Figure 4 This is a schematic diagram illustrating an example of enhanced 256-bit key generation in 5G according to embodiments of the present disclosure.

[0019] Figure 5 This is a schematic diagram illustrating an example of using a single bit flag for each key according to an embodiment of this disclosure.

[0020] Figure 6 This is a block diagram of an example computing device according to embodiments of the present disclosure.

[0021] Figure 7 This is a block diagram of a communication system according to an embodiment of the present disclosure. Detailed Implementation

[0022] The technical features, structural characteristics, objectives, and effects of the embodiments of this disclosure are described in detail below with reference to the accompanying drawings. Specifically, the terminology used in the embodiments of this disclosure is only used to describe the purpose of a particular embodiment and is not intended to limit the scope of this disclosure.

[0023] The technical solutions of this disclosure can be applied to various communication systems, such as the Global System for Mobile Communication (GSM), Code Division Multiple Access (CDMA), Wideband Code Division Multiple Access (WCDMA), General Packet Radio Service (GPRS), Long Term Evolution (LTE), LTE Frequency Division Duplex (FDD), LTE Time Division Duplex (TDD), Advanced Long Term Evolution (LTE-A), 5th Generation (5G) systems (also known as New Radio (NR) systems), evolution systems of NR systems, LTE-based access to unlicensed spectrum (LTE-U) systems, NR-based access to unlicensed spectrum (NR-U) systems, Universal Mobile Telecommunication System (UMTS), and Microwave Access Global Interoperability (MIG). Interoperability for microwave access (WiMAX) communication systems, wireless local area networks (WLAN), wireless fidelity (Wi-Fi), or other communication systems, etc.

[0024] User equipment (UE) can refer to an access terminal, subscriber unit, subscriber station, mobile station, remote station, remote terminal, mobile device, user terminal, terminal, wireless communication equipment, user agent, or user equipment. An access terminal can be a cellular wireless phone, cordless phone, session initiation protocol (SIP) phone, wireless local loop (WLL) station, personal digital assistant (PDA), handheld device with wireless communication capabilities, computing device, other processing devices coupled to a wireless modem, in-vehicle equipment, wearable device, terminal equipment in future 5G networks, and terminal equipment in future evolved public land mobile networks (PLMNs), etc.

[0025] Optionally, the communication system in this application embodiment can be applied to unlicensed spectrum, where unlicensed spectrum can also be regarded as shared spectrum, or the communication system in this application embodiment can also be applied to licensed spectrum, where licensed spectrum can also be regarded as non-shared spectrum.

[0026] Currently, 5G networks only support 128-bit encryption algorithms, while some other communication networks (e.g., non-5G) support both 128-bit and 256-bit encryption algorithms. In 5G, the key used for cryptography and integrity algorithms is 128-bit because 256-bit algorithms were not previously supported.

[0027] In networks that support both 128-bit and 256-bit algorithms, the application layer typically pre-configures the security algorithm and generates keys of appropriate size (128-bit or 256-bit) for the encryption algorithm. Because devices in non-5G networks (such as PCs and web servers) are generally more powerful, applications in non-5G networks tend to be less efficient compared to those in 5G networks. In non-5G communications, efficiency is not a primary concern; after authentication, both 128-bit and 256-bit encryption keys are generated, if supported.

[0028] Because communication in non-5G networks is end-to-end, there is no need to support intermediate communication nodes in the transport network. For example, a communication session using 256-bit security between a client and a server can pass through various nodes (e.g., routers, switches, hubs), but these nodes are unaware of the security algorithms used in the end-to-end communication.

[0029] Additionally, non-5G communication is typically non-mobile and does not support mobility or soft handover (e.g., failover before handover). When a communication session moves between different networks, the capabilities of each network do not need to be considered, for example, one network supports 128-bit security while another supports 256-bit security, because network devices are unaware of the security being used by the application layer.

[0030] Therefore, current solutions or related technologies do not support backward compatibility or interoperability, as these issues are specific to mobile network environments.

[0031] Some embodiments of this disclosure provide mechanisms for key generation and key usage indication in 5G to reduce the complexity of supporting 256-bit security by removing truncation operations in the current key generation process. This enables user equipment and network equipment to operate at the highest security level (e.g., 256-bit security) supported by both.

[0032] Additionally, when both 128-bit and 256-bit algorithms are supported, some embodiments of this disclosure provide mechanisms to maintain backward compatibility and interoperability during the transition from 128-bit to 256-bit security algorithms in 5G.

[0033] 128-bit and 256-bit algorithms (commonly referred to as 128-bit or 256-bit security) are encryption algorithms that use 128-bit or 256-bit key lengths to protect information, as defined by standards such as the Advanced Encryption Standard (AES). With the design lifespan of 128-bit encryption algorithms (like AES) approaching 20 years (for example, AES was officially released in 2002), the industry is transitioning to increasing the key size from 128 bits to 256 bits. Increasing the key size does not mean that 128-bit algorithms are broken or obsolete. 128-bit and 256-bit algorithms will coexist in next-generation mobile communication systems, possibly until 2030, 2040, or longer.

[0034] The transition from 128-bit to 256-bit security will be gradual and will only be completed when all network equipment (e.g., radio access networks and core network equipment) and user equipment (e.g., handsets) are fully upgraded. Until this transition is complete, backward compatibility and interoperability can be maintained between the network and user equipment with different security capabilities to ensure users can continue to seamlessly enjoy 5G services across different networks.

[0035] Some embodiments of this disclosure provide mechanisms that enable user equipment and network devices to operate at the security level they support (e.g., 256-bit security).

[0036] Some embodiments of this disclosure provide mechanisms to reduce the complexity of key generation for supporting 256-bit security by removing truncation operations from the current key generation process in 5G. This enables secure operations between user equipment and network devices to function at the highest security level (e.g., 256-bit security) supported by both.

[0037] Additionally, these embodiments provide a mechanism to indicate to the user equipment (UE) the size of the key (e.g., 128 bits) to be used during secure operation in a network that does not fully support 256-bit security. This mechanism can also be used to indicate the key size (e.g., 128 bits) to the UE when the network's security policy is set to use 128-bit secure operation.

[0038] Figure 1 A communication system 200 according to an embodiment of the present disclosure is illustrated. The communication system 200 is configured to implement some embodiments of the present disclosure. Some embodiments of the present disclosure can be implemented in the communication system using any suitably configured hardware and / or software. The communication system 200 may include a memory 201, a transceiver 202, and a processor 203 coupled to the memory 201 and the transceiver 202. The processor 203 may be configured to implement the functions, processes, and / or methods described herein. A layer of a radio interface protocol may be implemented in the processor 203. The memory 201 is operatively coupled to the processor 203 and stores various information to operate the processor 203. The transceiver 202 is operatively coupled to the processor 203 and transmits and / or receives radio signals. The processor 203 may include an application-specific integrated circuit (ASIC), other chipsets, logic circuits, and / or data processing devices. Memory 201 may include read-only memory (ROM), random access memory (RAM), flash memory, memory cards, storage media, and / or other storage devices. Transceiver 202 may include baseband circuitry for processing radio frequency signals. When embodiments are implemented in software, the techniques described herein may be implemented using modules (e.g., processes, functions, etc.) that perform the functions described herein. Modules may be stored in memory 201 and executed by processor 203. Memory 201 may be implemented within or outside of processor 203; in the case of external implementation, memory 201 may be communicatively coupled to processor 203 via various means known in the art.

[0039] In some embodiments, the processor 203 is configured to: generate at least one 256-bit security key for a 5G network in the UE, either without a truncation operation or by removing a truncation operation, to support 256-bit encryption and integrity protection, and to establish secure communication between the UE and the network device using the at least one 256-bit security key. This addresses the aforementioned and other problems in the related art. Furthermore, some of the proposed embodiments maintain backward compatibility, interoperability, and / or enhanced security.

[0040] Figure 2 A method 300 for supporting security in a user equipment (UE) according to embodiments of the present disclosure is illustrated. The method 300 for supporting security in a UE is configured to implement some embodiments of the present disclosure. Some embodiments of the present disclosure can be implemented in the method 300 for supporting security in a UE using any appropriately configured hardware and / or software. In some embodiments, the method 300 for supporting security in a UE includes: operation 302, in which the UE generates at least one 256-bit security key for a 5G network, either without a truncation operation or by removing a truncation operation, to support 256-bit encryption and integrity protection; and operation 304, in which the UE establishes secure communication between the UE and a network device using the at least one 256-bit security key. This can solve the aforementioned and other problems in the prior art. Furthermore, some of the proposed embodiments can maintain backward compatibility and interoperability and / or enhance security.

[0041] Some embodiments of this disclosure provide a mechanism to reduce the complexity of 256-bit security key generation by removing truncation operations during current 5G key generation, thereby enabling secure operations between user equipment (UE) and network devices to operate at the highest security level (such as 256-bit security) that both can support. Additionally, these embodiments provide a mechanism to indicate a key size (e.g., 128 bits) to the UE for secure operations in networks that do not fully support 256-bit security, and can also signal the key size when the network's security policy requires 128-bit security operations.

[0042] In some embodiments, the method further includes: when the 5G network does not support 256-bit secure operation, having the UE generate at least one 128-bit security key based on the least significant 128 bits of at least one 256-bit security key. In some embodiments, the method further includes indicating the size of the at least one security key to be used during secure operation via a key usage indicator or key flag. In some embodiments, the at least one security key is at least one 256-bit security key or at least one 128-bit security key. In some embodiments, the key usage indicator or key flag indicates whether the full 256 bits of the at least one 256-bit security key or the least significant 128 bits of the at least one 256-bit security key are used. In some embodiments, the key usage indicator or key flag is set for each security key generated in the UE, and the granularity of the key usage indicator or key flag is adjustable, thereby enabling the key usage indicator or key flag to be set for each security key or each group of security keys.

[0043] In some embodiments, the method further includes: generating at least one intermediate 256-bit security key by the UE based on at least one long-term security key of both the UE and the 5G network, wherein the at least one intermediate 256-bit security key is used to derive at least one final 128-bit security key or at least one final 256-bit security key for secure operation. In some embodiments, the method further includes: if the universal subscriber identity module (USIM) does not support 5G parameter storage, storing at least one intermediate 256-bit security key in the UE's non-volatile memory or the USIM by memory. In some embodiments, the method further includes storing the latest intermediate 256-bit security key in the UE's non-volatile memory or the USIM by memory after successful master authentication. In some embodiments, the method further includes replacing the old intermediate 256-bit security key with the latest intermediate 256-bit security key by the UE.

[0044] In some embodiments, the method further includes the UE performing security operations using at least one 128-bit security key for at least one communication layer and at least one 256-bit security key for at least another communication layer, based on operator security policies and / or key usage indicators or key flags. In some embodiments, during the authentication and key negotiation process, the UE generates security key material based on a long-term security key stored in the USIM, and the transceiver forwards the security key material to the UE's mobile equipment (ME) for further key derivation and storage. In some embodiments, at least one 256-bit security key is truncated to 128 bits for backward compatibility during the conversion from 128-bit to 256-bit security operations. In some embodiments, the key flag is a one-byte flag, wherein the one-byte flag is used to indicate the use of at least one security key, and at least one bit of the one-byte flag is reserved for future expansion to accommodate at least one additional security key.

[0045] When a UE capable of supporting 128-bit security algorithms (e.g., cryptographic and integrity algorithms) is authenticated, the keys used for encryption and integrity protection are generated as 128-bit keys. Currently, the key hierarchy supports 256-bit keys, starting from the root key (e.g., a long-term key) and going up to keys such as K. AUSF K SEAF K gNB and K AMF These intermediate keys are generated as 256-bit keys in both the UE and the 5G network, such as... Figure 3 As shown. However, these intermediate keys are not directly used for encryption or integrity protection. Instead, the keys used for these security operations are generated as 128-bit keys. Figure 3 The lower part shows the 128-bit key in the current 5G key generation process as specified in Technical Specification 33.501.

[0046] To support the full 256-bit key used for encryption and integrity protection, the key generated in the current 5G system (i.e., 128-bit key) NASint K NASenc K UPint K UPenc K RRCint and K RRCenc ,like Figure 3The key generation function (as shown) is extended to a full 256 bits. However, since a 128-bit key is still required for backward compatibility and interoperability during the transition from 128-bit security to 256-bit security (because not all devices within the network and roaming networks can support full 256-bit security operation), and considering that security is not end-to-end (e.g., encryption from one UE to another), performing the key generation function twice (once for generating the 128-bit key and once for generating the 256-bit key) would be inefficient. Therefore, in some embodiments of this disclosure, key generation is performed only once, such as... Figure 4 As shown. During this process, K NASint K NASenc K UPint K UPenc K RRCint and K RRCenc The key is generated as a 256-bit key. This method ensures that 128-bit and 256-bit keys can coexist, providing backward compatibility, while enabling a smoother transition to full 256-bit security in the future.

[0047] In some embodiments of this disclosure, key generation is performed only once, such as Figure 4 As shown. During this process, K NASint K NASenc K UPint K UPenc K RRCint and K RRCenc The generated key is a 256-bit key. This method allows 128-bit and 256-bit keys to coexist, ensuring backward compatibility and facilitating a smoother transition to full 256-bit security. The single execution of key generation reduces system complexity and processing overhead, allowing seamless operation in networks that support both 128-bit and 256-bit security algorithms. Therefore, the system can maintain interoperability across devices and network nodes that have not yet been fully upgraded to 256-bit security, providing a flexible solution for the network during the transition period.

[0048] Specifically, in some embodiments of this disclosure, key generation is performed only once, such as... Figure 4As shown in the diagram. During this process, security keys such as KNASint, KNASenc, KUPint, KUPenc, KRRCint, and KRRCenc are generated as 256-bit keys. This approach allows 128-bit and 256-bit security keys to coexist within the system, ensuring backward compatibility and providing a seamless transition path to full 256-bit security without introducing unnecessary complexity. The single execution of key generation significantly reduces system complexity by eliminating the need to independently generate separate 128-bit and 256-bit keys. In traditional scenarios, generating two sets of keys would require multiple key derivation processes, each consuming additional computational resources and increasing overall processing overhead. By generating only 256-bit keys and utilizing flexible mechanisms (such as key usage indicators) to determine whether to use the full 256 bits or the least significant 128 bits, the system ensures all security requirements are met while optimizing key generation efficiency.

[0049] This key generation method is particularly beneficial in environments where traditional and upgraded network infrastructures coexist. As many networks and devices are still transitioning from 128-bit security to 256-bit security, there is often a mix of devices capable of handling 128-bit encryption and newer systems capable of supporting 256-bit security algorithms. By pre-generating 256-bit keys, the system can dynamically adapt to the capabilities of the underlying network, enabling secure communication regardless of the security protocols used. Furthermore, this approach enhances the flexibility of the security architecture by enabling seamless operation in hybrid security environments. For example, if a device (UE) or network node connects to a legacy 5G network that only supports 128-bit security, the system can automatically utilize the least significant 128 bits of the generated 256-bit key without having to rerun the key generation process. This ensures that no additional processing burden is imposed on the device or network while still maintaining the required level of security for the connection.

[0050] In addition to simplifying the key generation process, this method also reduces the storage requirements for security keys. Since only a 256-bit key is stored, there is no need to maintain separate key sets for 128-bit and 256-bit operations. This consolidation minimizes the memory footprint of the security architecture, enabling more efficient use of available resources, especially in resource-constrained devices such as mobile handhelds. The ability to generate a 256-bit key in a single operation and selectively use either 128-bit or 256-bit segments based on network requirements also contributes to future scalability. As 5G networks develop and begin to fully adopt 256-bit encryption, the system can easily transition to using a full 256-bit key without any changes to the key generation process itself. This future-oriented design ensures that the network security architecture is flexible enough to support both current and future security needs.

[0051] Ultimately, this key generation method supports both backward compatibility and forward-looking security enhancements. It allows network operators and equipment manufacturers to continue supporting traditional 128-bit encryption during the transition to 256-bit security, while reducing the complexity of managing multiple key sets. This simplified approach ensures that security protocols can be implemented efficiently and consistently across various network environments, providing a robust and scalable solution for current and future communication systems.

[0052] Figure 4 In some embodiments, a corresponding key exists in the UE for each key in the network entity. The USIM may store the same long-term key K as that stored in the Authentication Credential Repository and Processing Function (ARPF). During the authentication and key negotiation process, the USIM can generate key material based on K and forward it to the ME. If provided by the home operator, the USIM may store the home network public key used to hide the Subscription Permanent Identifier (SUPI). The ME can generate K based on CK and IK received from the USIM. AUSF The generation of this key material is specific to the authentication method. When using 5GAKA, the ME can generate RES* based on RES. The UE can store the latest K. AUSF Or use the latest K after successfully completing the most recent master authentication. AUSF Replace the old K AUSF If USIM supports 5G parameter storage, then K AUSF It can be stored in the USIM. Otherwise, K AUSF It can be stored in the ME's non-volatile memory. When using 5G AKA as the authentication method, upon receiving a valid Non-Access Stratum (NAS) security mode command message from the Access and Mobility Management Function (AMF) (to use the newly generated K...), AUSF When the corresponding part of the exported context is obtained, the UE can consider the primary authentication successful and store the newly generated K. AUSF Or use the latest K AUSF Replace the old K AUSF In any case where the key generation EAP method is used for primary (re)authentication, upon receiving the EAP-Success message, the primary authentication can be considered successful, and the UE can store the newly generated key. AUSF Or use the latest K AUSFReplace the old K AUSF .

[0053] Figure 4 In some embodiments, it is shown that the ME can perform operations according to K. AUSF Generate K SEAF If USIM supports 5G parameter storage, then K SEAF It can be stored in the USIM. Otherwise, K SEAF It can be stored in the non-volatile memory of the ME. The ME can also execute K. AMF The generation of K. If USIM supports 5G parameter storage, then K can be used. AMF Stored in USIM; otherwise, K AMF It can be stored in the non-volatile memory of the ME. The ME is also responsible for generating data based on K. AMF All other subsequent keys exported. Any 5G security context or K key stored in the ME can be deleted from the ME in the following cases. AUSF and K SEAF a) Remove the USIM from the ME when the ME is powered on, b) Power on the ME and detect that the USIM is different from the USIM used to create the 5G security context, and / or c) Power on the ME and detect that the USIM does not exist.

[0054] In some embodiments of this disclosure, Figure 4 This paper demonstrates the final result of eliminating truncation operations during the key generation process to improve efficiency while still generating a 256-bit key. By removing the truncation step, the key generation process is simplified, reducing computational complexity and processing time. This method enables the direct generation of 256-bit keys without additional truncation operations, thereby optimizing overall security operations in 5G systems. The method ensures consistent generation of 256-bit keys while maintaining compatibility with existing systems that rely on 128-bit keys during the transition to full 256-bit security.

[0055] In some embodiments of this disclosure, to maintain backward compatibility and interoperability, a key usage indicator (or flag) is added to the 256-bit key to signal whether the full 256 bits of each key can be used or only the least significant 128 bits can be used. For example, the key usage indicator or flag is activated when a 128-bit key is required (such as when a UE roams to an older 5G network (VPLMN or visited network) that does not support full 256-bit security operation or only supports partial 256-bit security). If the indicator is a single bit, a value "1" indicates the use of the least significant 128 bits, while "0" indicates the use of the full 256-bit key. When the indicator signals 128-bit operation, the UE can access the key from the 256-bit key (K... NASint K NASenc KUPint K UPenc K RRCint and K RRCenc Extract the least significant 128 bits from the key and use them as the corresponding 128-bit key (K). NASint K NASenc K UPint K UPenc K RRCint and K RRCenc This mechanism ensures a seamless transition and compatibility with networks that do not fully support 256-bit security operations.

[0056] Specifically, in some embodiments of this disclosure, to maintain backward compatibility and interoperability, a key usage indicator (or flag) is introduced in conjunction with the 256-bit key to specify whether the entire 256 bits of each key should be used, or whether only the least significant 128 bits are required. This mechanism is particularly beneficial in scenarios where the UE (User Equipment) roams to older or less capable 5G networks (such as Visited Public Land Mobile Networks, VPLMNs) that do not fully support or only partially support 256-bit security operations. In this case, the key usage indicator is activated to signal the appropriate security level required by the network. The key usage indicator can be implemented as a single bit within the security framework, where a value "1" indicates that only the least significant 128 bits of the key should be used for security operations, while a value "0" indicates that the full 256-bit key should be used. For example, when a 128-bit key is required due to network limitations or interoperability constraints, the UE can automatically extract the least significant 128 bits from an existing 256-bit key. These 256-bit keys include K NASint K NASenc K UPint K UPenc K RRCint and K RRCenc And the extracted 128-bit segments of these keys are used for the corresponding security operations (i.e., K). NASint Used for NAS integrity, K NASenc Used for NAS encryption, K UPint Used for user plane integrity, K UPenc Used for user plane encryption, K RRCint Used for RRC integrity, and K RRCenc (Used for RRC encryption).

[0057] This key usage mechanism ensures seamless transitions between security levels without requiring the generation of separate 128-bit keys, which would otherwise increase the complexity of the key management process. By enabling the UE and network to dynamically adjust key usage based on network conditions, this solution ensures compatibility across various network infrastructures, particularly during migrations where some networks only support 128-bit security while others implement 256-bit security. Furthermore, this approach significantly optimizes performance in hybrid security environments, such as during roaming between different network areas, where relying solely on 256-bit security is impractical or inefficient. For example, older networks may not be equipped to handle the computational demands of 256-bit security, but with this flag mechanism, the UE can easily fall back to 128-bit security, ensuring secure communication without overloading network resources. This also simplifies the operational requirements for network providers by reducing the need to maintain multiple sets of keys or protocols, thereby simplifying the UE and network infrastructure.

[0058] Furthermore, this key flag mechanism provides a robust solution for the gradual transition from 128-bit security to 256-bit security in networks. As operators upgrade their systems to support higher security standards, the same UE can continue to operate efficiently in both older and newer networks without requiring major overhauls in key generation or management. This backward compatibility is crucial for maintaining service continuity for users, while allowing operators to enhance network security at their own pace. The solution is also scalable, meaning that as standards beyond 5G evolve, key usage indicators can be adapted to accommodate more complex security mechanisms. The flag itself can be extended to represent more granular security operations in the form of signals, allowing future implementations to selectively enable or disable certain levels of encryption or integrity protection based on the capabilities of both the UE and the network. This flexibility provides a future-proof mechanism for managing secure operations as communication standards evolve. Introducing key usage indicators or flags within the 256-bit key framework enhances the flexibility and interoperability of secure operations across different network environments. It enables a smooth and efficient transition between 128-bit and 256-bit security, minimizing operational complexity and ensuring long-term scalability while maintaining a high level of security for user communications.

[0059] In some embodiments of this disclosure, for additional flexibility, the granularity of key usage indicators or key flags can be per key (e.g., one flag for K). NASint A flag is used for K NASenc ) or each key group (e.g., a flag for K) NASint and K NASenc Both can be used to set this. Figure 5An example of flags used for each key currently defined in 5G is shown. In this example, one byte is used to represent the flags used for each of the six keys (K). NASint K NASenc K UPint K UPenc K RRCint and K RRCenc The flag is left with two bits for future expansion. This approach not only provides the flexibility to manage the use of 128-bit or 256-bit keys on a per-key or per-group basis, but also allows for scalability when adding new keys to the system in the future.

[0060] Specifically, in some embodiments of this disclosure, to provide additional flexibility and control over security operations, the granularity of key usage indicators or key flags can be configured for individual keys or for groups of keys. For example, a separate flag can be assigned to each key, such as a flag for K. NASint A flag is used for K NASenc This allows for fine-grained control over the security level applied to each key. Alternatively, a single flag can be used for a set of related keys, such as K. NASint and K NASenc This allows for a more streamlined configuration where both keys share the same security settings.

[0061] Figure 5 An example is shown where a key usage indicator is assigned to each key currently defined in 5G. In this example, a single byte is used to represent a flag for the following six different keys: K NASint K NASenc K UPint K UPenc K RRCint and K RRCenc This implementation leaves two extra bits within the byte for future expansion, allowing the system to accommodate more keys or additional functionality required by future 5G or non-5G standards. By implementing this flexible flag system, network operators and equipment manufacturers can dynamically adjust the security level applied to each key based on network and UE capabilities. For example, in a network that fully supports 256-bit security, the flag can indicate that the full 256-bit key is used for both encryption and integrity protection. Conversely, for backward-compatible operation in a network that only supports 128-bit security, the flag can be signaled to indicate that only the least significant 128 bits of the key are used, ensuring seamless interoperability.

[0062] This approach also offers scalability. As 5G networks evolve and new key types are introduced (e.g., keys associated with new security features or communication protocols), the remaining two bits in the byte can be used to represent additional flags, eliminating the need to redesign the flag system. Furthermore, the system can be scaled up to use more than one byte if additional keys or finer-grained control over key usage is required in future implementations. The use of a flexible key flag system also optimizes memory and processing resources. The system can use a single, unified process where the applicable key length and operations are dynamically determined using key flags, rather than maintaining separate processes for 128-bit and 256-bit key operations. This reduces the overall complexity and processing load on both the UE and network equipment, enhancing performance without compromising security. Overall, this flexible and scalable approach to key usage indicators provides a robust mechanism for maintaining backward compatibility while preparing for future security upgrades, ensuring effective fulfillment of current and future 5G security requirements.

[0063] This granularity allows for the flexibility of applying different security levels to various communication layers within the network, depending on the operator's security policy. For example, an operator can choose to implement 128-bit security for NAS layer communications while utilizing 256-bit security for UP and RRC layer communications. This enables a more customized security approach, optimizing performance where higher levels of protection are required, such as in user plane (UP) and radio resource control (RRC) communications, without unnecessarily burdening other layers where 128-bit security might be sufficient.

[0064] By allowing different security configurations for each communication layer, the system can dynamically adapt to different levels of standards or operational requirements. For example, UP communications, which handle user data, typically require higher security due to the sensitive nature of the transmitted data. In contrast, NAS layer communications, which handle signaling and mobility management, may not always require the same level of encryption, thus reducing overhead and improving system efficiency.

[0065] Furthermore, this flexibility allows network operators to balance security and performance based on specific circumstances or network conditions. In some scenarios where resources are limited or interoperability with legacy systems is prioritized, 128-bit security may be the preferred choice across all layers. However, in more secure environments, operators can selectively apply 256-bit security to critical layers without compromising overall network performance. This ability to fine-tune security levels ensures that the network remains robustly protected against potential threats while remaining adaptable to evolving standards and changing device capabilities. Operators can tailor security policies as needed, leveraging the granularity of key usage indicators to efficiently meet current and future security requirements.

[0066] By simplifying the existing key generation process in 5G, some embodiments of this disclosure offer significant benefits to operators, UE vendors, and network equipment vendors. The simplified key generation process reduces complexity, making it easier to implement and manage secure operations. This simplification is particularly advantageous during the migration from 128-bit to 256-bit secure operations, as it allows for a smoother transition while supporting higher levels of security.

[0067] By eliminating unnecessary steps, such as truncation operations, and introducing flexible key usage indicators, some implementations reduce the operational burden on network operators and vendors. This results in more efficient key management, less processing overhead, and improved system performance without compromising security. Furthermore, this simplified approach ensures backward compatibility, making it easier for operators to maintain interoperability with legacy equipment and networks that still rely on 128-bit security.

[0068] Furthermore, some implementations benefit the industry as a whole by facilitating a gradual and seamless transition to higher levels of security. With the development of 5G networks and the increasing demand for stronger security, the ability to smoothly transition from 128-bit security to 256-bit security becomes crucial. These implementations enable industry stakeholders to adopt more advanced security measures without causing significant disruption to existing network operations or requiring costly upgrades.

[0069] Overall, some of these implementations support the industry's long-term goal of enhancing security in 5G and future mobile communication systems. They provide practical and efficient solutions for expanding secure operations, ensuring networks can meet growing security demands while maintaining flexibility and compatibility across different generations of network infrastructure.

[0070] Alternatives to the solutions proposed in some embodiments of this disclosure include methods that can solve key generation but lack the flexibility and efficiency offered by the disclosed embodiments.

[0071] An alternative is to generate both 128-bit and 256-bit keys for the UE and network during the security key generation process. While this ensures that both key lengths are available, it is wasteful in terms of storage and processing resources. At any given time, either a 128-bit or 256-bit key can be used, but neither can be used simultaneously. Therefore, generating two sets of keys leads to unnecessary overhead, thus reducing overall system efficiency.

[0072] Another alternative is to pre-configure the use of 128-bit or 256-bit keys during the authentication and key negotiation process. While this approach reduces the complexity of generating both key lengths, it lacks the flexibility to adjust security levels across different layers. For example, it will not allow for separate security operations, such as using 128-bit security operations at the UP and RRC layers while simultaneously using 256-bit security operations at the NAS layer. This alternative limits the system's ability to dynamically adjust security based on operator policies or network conditions, thus limiting its adaptability to changing security requirements.

[0073] While these alternatives are feasible, they do not offer the same level of flexibility, efficiency, or granularity as the solutions presented in some embodiments of this disclosure. In contrast, the disclosed embodiments provide a more balanced and adaptable approach to key generation and secure operations, optimizing performance and resource usage while supporting future scalability.

[0074] Some implementations offer the following commercial benefits: 1. Solving the aforementioned problems in related technologies. 2. Solving other problems. 3. Maintaining backward compatibility and interoperability. 4. Enhancing security. 5. Providing good communication performance. 6. Providing high reliability. 7. Some embodiments of this disclosure are intended for use by chipset suppliers, video system development suppliers, automobile manufacturers (including cars, trains, trucks, buses, bicycles, motorcycles, helmets, etc.), drone (unmanned aerial vehicle) manufacturers, smartphone manufacturers, and manufacturers of communication equipment for public safety purposes, such as gaming, conference / seminar, and educational augmented reality (AR) / virtual reality (VR) / mixed reality (MR) devices. Some embodiments of this disclosure are combinations of "technologies / processes" that can be adopted in video standards to produce end products. Some embodiments of this disclosure present technical mechanisms. At least one solution, method, system, and apparatus proposed in some embodiments of this disclosure can be used in current and / or new / future standards for communication systems (such as Artificial Intelligence of Things Device (AIoT) devices, nodes (UE / base station (BS)) and / or communication systems). Compatible products follow at least one solution, method, system, and apparatus proposed in some embodiments of this disclosure. The proposed solutions, methods, systems, and apparatus are widely used in AIoT devices, nodes (UE / BS), and / or communication systems. Implementations of at least one solution, method, system, and apparatus proposed in some embodiments of this disclosure may include at least one modification to the communication methods and apparatus for standardization.

[0075] Figure 6 This is an example of a computing device 1200 according to embodiments of the present disclosure. Any suitable computing device can be used to perform the operations described herein. For example, Figure 6 Examples of computing devices 1200 that can implement the apparatus and methods of the embodiments described above using any suitably configured hardware and / or software are shown. In some embodiments, computing device 1200 may include processor 1412, which is communicatively coupled to memory 1414 and executes computer-executable program code and / or accesses information stored in memory 1414. Processor 1412 may include a microprocessor, application-specific integrated circuit (“ASIC”), state machine, or other processing device. Processor 1412 may include any one of a plurality of processing devices, including one processing device. Such a processor may include a computer-readable medium storing instructions or be able to communicate with a computer-readable medium storing instructions that, when executed by processor 1412, cause the processor to perform the operations described herein.

[0076] Memory 1414 may include any suitable non-transitory computer-readable medium. Computer-readable medium may include any electronic, optical, magnetic, or other storage device capable of providing computer-readable instructions or other program code to a processor. Non-limiting examples of computer-readable media include disks, memory chips, read-only memory (ROM), random access memory (RAM), application-specific integrated circuits (ASICs), configured processors, optical storage devices, magnetic tape or other magnetic storage devices, or any other medium from which instructions can be read by a computer processor. Instructions may include processor-specific instructions generated by a compiler and / or interpreter from code written in any suitable computer programming language, including, for example, C, C++, C#, Visual Basic, Java, Python, Perl, JavaScript, and ActionScript.

[0077] The computing device 1200 may also include a bus 1416. The bus 1416 may communicatively couple one or more components of the computing device 1200. The computing device 1200 may also include multiple external or internal devices, such as input or output devices. For example, the computing device 1200 is shown having an input / output (“I / O”) interface 1418 that can receive input from one or more input devices 1420 or provide output to one or more output devices 1422. One or more input devices 1420 and one or more output devices 1422 may be communicatively coupled to the I / O interface 1418. The communicative coupling may be implemented via any suitable means (e.g., via a connection to a printed circuit board, via a cable, via wireless communication, etc.). Non-limiting examples of the input device 1420 include a touchscreen (e.g., one or more cameras for imaging a touch area or a pressure sensor for detecting pressure changes caused by a touch), a mouse, a keyboard, or any other device that can be used to generate input events in response to physical actions of a user of the computing device. Non-limiting examples of output device 1422 include liquid crystal display (LCD) screens, external monitors, speakers, or any other device that can be used to display or otherwise present output generated by a computing device.

[0078] The computing device 1200 can execute program code that configures the processor 1412 to perform one or more operations described above with respect to the methods of the embodiments described in the foregoing. The program code may reside in memory 1414 or any suitable computer-readable medium and may be executed by the processor 1412 or any other suitable processor.

[0079] The computing device 1200 may also include at least one network interface device 1424. The network interface device 1424 may include any device or group of devices adapted to establish wired or wireless data connections to one or more data networks 1428. Non-limiting examples of the network interface device 1424 include Ethernet network adapters, modems, etc. The computing device 1200 may transmit messages as electronic or optical signals via the network interface device 1424.

[0080] Figure 7 This is a block diagram of an example communication system 1500 according to embodiments of the present disclosure. The embodiments described herein can be implemented in the communication system 1500 using any appropriately configured hardware and / or software. Figure 7 A communication system 1500 is shown, which includes at least radio frequency (RF) circuitry 1510, baseband circuitry 1520, application circuitry 1530, memory / storage device 1540, display 1550, camera 1560, sensor 1570, and input / output (I / O) interface 1580, all of which are coupled to each other as shown.

[0081] Application circuitry 1530 may include circuitry such as, but not limited to, one or more single-core or multi-core processors. The processor may include any combination of general-purpose processors and special-purpose processors (such as graphics processors, application processors). The processor may be coupled to a memory / storage device and configured to execute instructions stored in the memory / storage device to enable various applications and / or operating systems running on the system. Communication system 1500 may execute program code that configures application circuitry 1530 to perform one or more of the operations described above with respect to the methods of the embodiments described above. The program code may reside in application circuitry 1530 or any suitable computer-readable medium and may be executed by application circuitry 1530 or any other suitable processor.

[0082] The baseband circuit 1520 may include circuitry such as, but not limited to, one or more single-core or multi-core processors. The processor may include a baseband processor. The baseband circuitry can handle various radio control functions that enable communication with one or more radio networks via RF circuitry. Radio control functions may include, but are not limited to, signal modulation, encoding, decoding, and radio frequency shifting. In some embodiments, the baseband circuitry can provide communication compatible with one or more radio technologies. For example, in some embodiments, the baseband circuitry may support communication with the Evolved Universal Terrestrial Radio Access Network (EUTRAN) and / or other Wireless Metropolitan Area Networks (WMAN), Wireless Local Area Networks (WLAN), and Wireless Personal Area Networks (WPAN). Embodiments of the baseband circuitry configured to support radio communication with more than one radio protocol may be referred to as a multi-mode baseband circuitry.

[0083] In various embodiments, baseband circuit 1520 may include circuitry for operating with signals not strictly considered to be at baseband frequencies. For example, in some embodiments, the baseband circuitry may include circuitry for operating with signals having an intermediate frequency (IF), which is between the baseband frequency and the radio frequency (RF). RF circuit 1510 may use modulated electromagnetic radiation through a non-solid-state medium to achieve communication with a wireless network. In various embodiments, RF circuitry may include switches, filters, amplifiers, etc., to facilitate communication with a wireless network. In various embodiments, RF circuitry 1510 may include circuitry for operating with signals not strictly considered to be at the radio frequency (RF). For example, in some embodiments, RF circuitry may include circuitry for operating with signals having an intermediate frequency (IF), which is between the baseband frequency and the RF frequency.

[0084] In various embodiments, the transmitter circuitry, control circuitry, or receiver circuitry discussed above with respect to the apparatus and methods of the above embodiments may be wholly or partially embodied in one or more of the RF circuitry, baseband circuitry, and / or application circuitry. As used herein, “circuit” may refer to, be part of, or include application-specific integrated circuits (ASICs), electronic circuitry, processors (shared, dedicated, or grouped) and / or memories (shared, dedicated, or grouped), combinational logic circuitry, and / or other suitable hardware components that provide the described functionality, executing one or more software or firmware programs. In some embodiments, electronic device circuitry may be implemented in one or more software or firmware modules, or the functionality associated with the circuitry may be implemented by one or more software or firmware modules. In some embodiments, some or all of the components of the baseband circuitry, application circuitry, and / or memory / storage device may be implemented together on a system-on-a-chip (SOC). Memory / storage device 1540 may be used to load and store, for example, data and / or instructions for the system. Memory / storage device for one embodiment may include any combination of suitable volatile memory (such as dynamic random access memory (DRAM)) and / or non-volatile memory (such as flash memory).

[0085] In various embodiments, I / O interface 1580 may include one or more user interfaces designed to enable a user to interact with the system and / or peripheral component interfaces designed to enable peripheral components to interact with the system. User interfaces may include, but are not limited to, physical keyboards or keypads, touchpads, speakers, microphones, etc. Peripheral component interfaces may include, but are not limited to, non-volatile memory ports, universal serial bus (USB) ports, audio jacks, and power interfaces. In various embodiments, sensor 1570 may include one or more sensing devices to determine environmental conditions and / or location information relevant to the system. In some embodiments, sensors may include, but are not limited to, gyroscope sensors, accelerometers, proximity sensors, ambient light sensors, and positioning units. Positioning units may also be part of or interact with baseband and / or RF circuitry to communicate with components of a positioning network (e.g., Global Positioning System (GPS) satellites).

[0086] In various embodiments, display 1550 may include a display, such as a liquid crystal display (LCD) and a touchscreen display. In various embodiments, communication system 1500 may be a mobile computing device, such as, but not limited to, a laptop, tablet, netbook, ultrabook, smartphone, AR / VR glasses, etc. In various embodiments, the system may have more or fewer components and / or different architectures. Where appropriate, the methods described herein may be implemented as a computer program. The computer program may be stored on a storage medium, such as a non-transitory storage medium.

[0087] Those skilled in the art will understand that each unit, algorithm, and step described and disclosed in the embodiments of this disclosure is implemented using electronic hardware or a combination of computer software and electronic hardware. Whether a function operates in hardware or software depends on the application conditions and the design requirements of the technical solution. Those skilled in the art can implement the function for each specific application in different ways, and such implementation should not exceed the scope of this disclosure. Those skilled in the art will understand that since the working processes of the above-described systems, devices, and units are substantially the same, they can refer to the working processes of the systems, devices, and units in the above embodiments. For ease of description and simplification, these working processes will not be described in detail again.

[0088] It should be understood that the systems, devices, and methods disclosed in the embodiments of this disclosure can be implemented in other ways. The above embodiments are merely exemplary. The division of units is based solely on logical function, while other divisions exist in the implementation. Multiple units or components can be combined or integrated into another system. It is also possible to omit or skip some features. On the other hand, the mutual coupling, direct coupling, or communication coupling shown or discussed operates indirectly or communicatively through some ports, devices, or units in an electrical, mechanical, or other form.

[0089] The units used for illustration may or may not be physically separate. The units used for display may or may not be physical units, i.e., located in one location or distributed across multiple network units. Some or all of the units may be used depending on the purpose of the embodiment. Furthermore, each functional unit in each embodiment may be integrated into a processing unit, or physically independent, or integrated into a processing unit having two or more units.

[0090] If a software functional unit is implemented and used and sold as a product, it can be stored in a readable storage medium in a computer. Based on this understanding, the technical solutions proposed in this disclosure can be implemented substantially or partially in the form of a software product. Alternatively, a portion of the technical solution that is beneficial to conventional technology can be implemented in the form of a software product. The software product in the computer is stored in a storage medium, including multiple commands for a computing device (such as a personal computer, server, or network device) to execute all or part of the steps disclosed in the embodiments of this disclosure. The storage medium includes a USB flash drive, a portable hard drive, a read-only memory (ROM), a random access memory (RAM), a floppy disk, or other types of media capable of storing program code.

[0091] While this disclosure has been described in conjunction with what are considered to be the most practical and preferred embodiments, it should be understood that this disclosure is not limited to the disclosed embodiments, but is intended to cover various arrangements made without departing from the broadest interpretation of the appended claims.

Claims

1. A method for supporting security in a user equipment (UE), comprising: The UE generates at least one 256-bit security key for the 5G network, either without a truncation operation or by removing the truncation operation, to support 256-bit encryption and integrity protection. as well as The UE uses the at least one 256-bit security key to establish secure communication between the UE and the network device.

2. The method according to claim 1, further comprising: When the 5G network does not support 256-bit security operation, the UE generates at least one 128-bit security key based on the least valid 128 bits of the at least one 256-bit security key.

3. The method according to claim 1 or 2, further comprising: The size of at least one security key to be used during secure operation is indicated by a key usage indicator or key flag.

4. The method according to claim 3, wherein, The at least one security key is either the at least one 256-bit security key or the at least one 128-bit security key.

5. The method according to claim 4, wherein, The key usage indicator or the key flag indicates whether the full 256 bits of the at least one 256-bit security key are used or the least valid 128 bits of the at least one 256-bit security key are used.

6. The method according to any one of claims 3 to 5, wherein, The key usage indicator or the key flag is set for each security key generated in the UE, and the granularity of the key usage indicator or the key flag is adjustable, thereby enabling the key usage indicator or the key flag to be set for each security key or each group of security keys.

7. The method according to any one of claims 1 to 6, further comprising: The UE generates at least one intermediate 256-bit security key based on at least one long-term security key of the UE and the 5G network, wherein the at least one intermediate 256-bit security key is used to derive at least one final 128-bit security key or at least one final 256-bit security key for secure operation.

8. The method according to claim 7, further comprising: In cases where the Universal Subscriber Identity Module (USIM) does not support 5G parameter storage, the at least one intermediate 256-bit security key is stored in the non-volatile memory of the UE or in the USIM by a memory.

9. The method according to claim 7 or 8, further comprising: After successful master authentication, the memory stores the latest intermediate 256-bit security key in the UE's non-volatile memory or the USIM.

10. The method of claim 9, further comprising: The UE replaces the old middle 256-bit security key with the latest middle 256-bit security key.

11. The method according to any one of claims 1 to 10, further comprising: The UE performs security operations based on the operator's security policy and / or the key usage indicator or the key flag, using at least one 128-bit security key for at least one communication layer and at least one 256-bit security key for at least another communication layer.

12. The method according to any one of claims 7 to 11, wherein, During the authentication and key negotiation process, the UE generates security key material based on the long-term security key stored in the Universal Subscriber Identity Module (USIM), and the transceiver forwards the security key material to the UE's mobile device (ME) for further key export and storage.

13. The method according to any one of claims 1 to 12, wherein, The at least one 256-bit security key is truncated to 128 bits for backward compatibility during the transition from 128-bit security operation to 256-bit security operation.

14. The method according to any one of claims 3 to 13, wherein, The key flag is a one-byte flag, and the one-byte flag is used to indicate the use of at least one security key, and at least one bit of the one-byte flag is reserved for future expansion to accommodate at least one additional security key.

15. A communication system, comprising: Memory; transceiver; and A processor coupled to the memory and the transceiver; The processor is configured to execute: In the user equipment (UE), at least one 256-bit security key for 5G networks is generated without a truncation operation or by removing the truncation operation to support 256-bit encryption and integrity protection. as well as Secure communication is established between the UE and the network device using the at least one 256-bit security key.

16. The communication system according to claim 15, wherein, When the 5G network does not support 256-bit security operation, the processor is configured to generate at least one 128-bit security key based on the least valid 128 bits of the at least one 256-bit security key.

17. The communication system according to claim 15 or 16, wherein, The processor is configured to indicate the size of at least one security key to be used during secure operation via a key usage indicator or key flag.

18. The communication system according to claim 17, wherein, The at least one security key is either the at least one 256-bit security key or the at least one 128-bit security key.

19. The communication system according to claim 18, wherein, The key usage indicator or the key flag indicates whether the full 256 bits of the at least one 256-bit security key are used or the least valid 128 bits of the at least one 256-bit security key are used.

20. The communication system according to any one of claims 17 to 19, wherein, The key usage indicator or the key flag is set for each security key generated in the UE, and the granularity of the key usage indicator or the key flag is adjustable, thereby enabling the key usage indicator or the key flag to be set for each security key or each group of security keys.

21. The communication system according to any one of claims 15 to 20, wherein, The processor is configured to generate at least one intermediate 256-bit security key based on at least one long-term security key of the UE and the 5G network, wherein the at least one intermediate 256-bit security key is used to derive at least one final 128-bit security key or at least one final 256-bit security key for secure operation.

22. The communication system according to claim 21, wherein, The memory is configured to store the at least one intermediate 256-bit security key in the non-volatile memory of the UE or in the USIM, provided that the Universal User Identity Module (USIM) does not support 5G parameter storage.

23. The communication system according to claim 21 or 22, wherein, The memory is configured to store the latest intermediate 256-bit security key in the UE's non-volatile memory or the USIM after successful master authentication.

24. The communication system according to claim 23, wherein, The processor is configured to replace the old middle 256-bit security key with the latest middle 256-bit security key.

25. The communication system according to any one of claims 15 to 24, wherein, The processor is configured to perform security operations based on the operator's security policy and / or the key usage indicator or the key flag, using at least one 128-bit security key for at least one communication layer and at least one 256-bit security key for at least another communication layer.

26. The communication system according to any one of claims 21 to 25, wherein, During the authentication and key negotiation process, the processor is configured to generate security key material based on the long-term security key stored in the Universal Subscriber Identity Module (USIM), and the transceiver is configured to forward the security key material to the UE's mobile device (ME) for further key export and storage.

27. The communication system according to any one of claims 15 to 26, wherein, The at least one 256-bit security key is truncated to 128 bits for backward compatibility during the transition from 128-bit security operation to 256-bit security operation.

28. The communication system according to any one of claims 17 to 27, wherein, The key flag is a one-byte flag, and the one-byte flag is used to indicate the use of at least one security key, and at least one bit of the one-byte flag is reserved for future expansion to accommodate at least one additional security key.

29. A non-transitory machine-readable storage medium storing instructions that, when executed by a computer, cause the computer to perform the method according to any one of claims 1 to 14.

30. A chip, comprising: The processor is configured to invoke and run a computer program stored in memory to cause a device in which the chip is mounted to perform the method according to any one of claims 1 to 14.

31. A computer-readable storage medium storing a computer program, wherein the computer program causes a computer to perform the method according to any one of claims 1 to 14.

32. A computer program product comprising a computer program, wherein the computer program causes a computer to perform the method according to any one of claims 1 to 14.

33. A computer program, wherein, The computer program causes the computer to perform the method according to any one of claims 1 to 14.

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