MAC CE security protection

Abstract

Embodiments of this disclosure provide a solution for MAC CE security protection. In the solution, the device receives or transmits a MAC message including at least one MAC PDU. The at least one MAC PDU includes at least: a MAC CE Service Data Unit (SDU) and protection-related information of the MAC message. The MAC CE SDU includes a payload portion, and at least the MAC CE SDU and the protection-related information are protected for integrity.

Description

Technical Field

[0001] Various exemplary embodiments of this disclosure generally relate to the telecommunications field, and more specifically to methods, apparatuses, devices, and computer-readable storage media for security protection of Media Access Control (MAC) control elements (CE). Background Technology

[0002] A communication network can be used as a facility to enable communication between two or more communication devices or to provide communication devices with access to a data network. A mobile or wireless communication network is an example of a communication network. Communication devices may be serviced by an application server.

[0003] Communication networks can operate according to standards provided by organizations such as the 3rd Generation Partnership Project (3GPP) or the European Telecommunications Standards Institute (ETSI). Examples of standards provided by 3GPP are the so-called 3GPP standards used for generations of cellular technology, such as the 3GPP standards for 4G, 5G, 6G, etc. Summary of the Invention

[0004] In a first aspect of this disclosure, an apparatus is provided. The apparatus includes at least one processor; and at least one memory storing instructions, which, when executed by the at least one processor, cause the apparatus to at least: receive or transmit a MAC message, the MAC message including at least one MAC Protocol Data Unit (PDU). The at least one MAC PDU includes at least a MAC CE Service Data Unit (SDU) and protection-related information of the MAC message. The MAC CE SDU includes a payload portion, and at least the MAC CE SDU and the protection-related information are protected for integrity.

[0005] In a second aspect of this disclosure, a method is provided. The method includes: receiving or transmitting a MAC message, the MAC message including at least one MAC PDU. The at least one MAC PDU includes at least: a MAC CE SDU and protection-related information of the MAC message. The MAC CE SDU includes a payload portion, and at least the MAC CE SDU and the protection-related information are protected for integrity.

[0006] In a third aspect of this disclosure, an apparatus is provided. The apparatus includes components for receiving or transmitting a MAC message, the MAC message including at least one MAC PDU. The at least one MAC PDU includes at least: a MAC CE SDU and protection-related information of the MAC message. The MAC CE SDU includes a payload portion, and at least the MAC CE SDU and the protection-related information are protected for integrity.

[0007] In a fourth aspect of this disclosure, a computer-readable medium is provided. The computer-readable medium includes instructions stored thereon for causing a device to at least execute the method according to the second aspect.

[0008] It should be understood that the summary portion is not intended to identify key or essential features of the embodiments of this disclosure, nor is it intended to limit the scope of this disclosure. Other features of this disclosure will become readily apparent from the following description. Attached Figure Description

[0009] Some exemplary embodiments will now be described with reference to the accompanying drawings, in which: Figure 1 An example communication environment in which example embodiments of the present disclosure may be implemented is shown; Figure 2 The LTM cell handover command MAC CE is shown. Figure 3 A schematic diagram of the LTM cell handover command MAC CE is shown; Figure 4 An overview of the MAC structure is shown; Figure 5A An example DL MAC PDU is shown; Figure 5B An example UL MAC PDU is shown; Figure 6 This illustrates the key hierarchy generation process in 5GS (5G system); Figure 7A An example data encryption process is shown; Figure 7B An example derivation of MAC-I / NAS-MAC or XMAC-I / XNAS-MAC is shown; Figure 8 The protocol stack for supporting RRC and NAS connectivity for Integrated Access and Backhaul Mobile Terminals (IAB-MT) is shown. Figure 9 A flowchart is shown for an example method of implementing MAC CE security protection at a device according to some example embodiments of the present disclosure; Figure 10A An example MAC CE security framework according to some embodiments of this disclosure is shown; Figure 10B Another example MAC CE security framework according to some embodiments of this disclosure is shown; Figure 11A and Figure 11B Two example procedures for key derivation for MAC CE security protection are shown respectively; Figure 12AAn example process for generating a keystream for MAC CE security protection according to some embodiments of this disclosure is shown; Figure 12B An example process for generating a keystream for MAC CE security protection according to some embodiments of this disclosure is shown; Figure 13 A simplified block diagram of a device suitable for implementing example embodiments of the present disclosure is shown; and Figure 14 A block diagram of an example computer-readable medium according to some example embodiments of the present disclosure is shown.

[0010] Throughout the accompanying drawings, the same or similar reference numerals denote the same or similar elements. Detailed Implementation

[0011] The principles of this disclosure will now be described with reference to some exemplary embodiments. It should be understood that these embodiments are described merely for illustration and to help those skilled in the art understand and implement this disclosure, and do not imply any limitation on the scope of this disclosure. The embodiments described herein can be implemented in various ways other than those described below.

[0012] In the following description and claims, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains.

[0013] References to "an embodiment," "embodiment," "example embodiment," etc., in this disclosure indicate that the described embodiment may include a particular feature, structure, or characteristic, but not every embodiment needs to include that particular feature, structure, or characteristic. Furthermore, such phrases do not necessarily refer to the same embodiment. Moreover, when a particular feature, structure, or characteristic is described in connection with an embodiment, whether explicitly described or not, it is believed that its influence on such feature, structure, or characteristic in conjunction with other embodiments is within the knowledge of those skilled in the art.

[0014] It should be understood that although various elements may be described herein using prefixes such as “first,” “second,” etc., these elements should not be limited by these terms. These terms are used only to distinguish one element from another, and they do not restrict the order of the terms. For example, without departing from the scope of the exemplary embodiments, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element. As used herein, the term “and / or” includes any and all combinations of one or more of the listed terms.

[0015] As used herein, “at least one of the following: ” and “at least one of ” and similar wording, where the list of two or more elements is connected by “and” or “or”, means at least any one of the elements, or at least any two or more of the elements, or at least all of the elements.

[0016] As used herein, unless explicitly stated otherwise, the execution step “in response to A” does not indicate that the step must be performed immediately after “A” occurs, and may include one or more intermediate steps.

[0017] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments. As used herein, the singular forms “a,” “an,” and “the” are also intended to include the plural forms unless the context clearly indicates otherwise. It will be further understood that the terms “comprising,” “including,” “having,” “containing,” and / or “including” as used herein specify the presence of stated features, elements, and / or components, etc., but do not exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof.

[0018] As used in this application, the term "circuit system" may refer to one or more of the following: (a) Hardware circuit implementation only (such as implementation in analog and / or digital circuits only), and (b) A combination of hardware circuitry and software, such as (if applicable): (i) A combination of (multiple) analog and / or digital hardware circuits and software / firmware, and (ii) Any part of a hardware processor (including multiple digital signal processors, software, and multiple memories, which work together to enable a device (such as a mobile phone or server) to perform various functions), and (c) (Multiple) hardware circuits and / or (multiple) processors, such as (multiple) microprocessors or a portion thereof, which require software (e.g. firmware) to operate, but may not exist when the software is not required to operate.

[0019] The definition of "circuit system" applies to all uses of the term in this application, including any claim. As yet another example, as used in this application, the term "circuit system" also covers implementations of hardware circuitry or processors (or processors) or hardware circuitry or processors and their accompanying software and / or firmware. The term "circuit system" also covers, for example (and if applicable to a particular claim element), baseband integrated circuits or processor integrated circuits for mobile devices or similar integrated circuits in servers, cellular network devices, or other computing or networking devices.

[0020] As used herein, the term "communication network" refers to a network that conforms to any suitable communication standard, such as New Radio (NR), Long Term Evolution (LTE), LTE-A Advanced (LTE-A), Wideband Code Division Multiple Access (WCDMA), High-Speed ​​Packet Access (HSPA), Narrowband Internet of Things (NB-IoT), etc. Furthermore, communication between terminal devices and network devices in a communication network can be performed according to any suitable intergenerational communication protocol, including but not limited to first-generation (1G), second-generation (2G), 2.5G, 2.75G, third-generation (3G), fourth-generation (4G), 4.5G, fifth-generation (5G), 5G Advanced, 5.5G, sixth-generation (6G) communication protocols and / or any other currently known or future-developed protocols. Embodiments of this disclosure can be applied to a variety of communication systems. Given the rapid development in communications, there will naturally be future types of communication technologies and systems that can implement this disclosure. The scope of this disclosure should not be limited to the aforementioned systems only.

[0021] As used herein, the term "network device" refers to a node in a communication network through which terminal devices access the network and receive services. Network devices can refer to base stations (BS) or access points (APs), such as Node B (NodeB or NB), evolved Node B (eNodeB or eNB), NR NB (also known as gNB), Remote Radio Unit (RRU), Radio Head (RH), Remote Radio Head (RRH), repeater, Integrated Access and Backhaul (IAB) node, low-power nodes (such as femtonodes, piconodes), non-terrestrial network (NTN) or non-terrestrial network equipment (such as satellite network equipment, low Earth orbit (LEO) satellites, and geostationary Earth orbit (GEO) satellites), spacecraft network equipment, etc., depending on the terminology and technology employed. In some example embodiments, the Radio Access Network (RAN) split architecture includes centralized units (CUs) and distributed units (DUs). This architecture can be applied to IAB donor nodes. An IAB node includes a mobile terminal (IAB-MT) portion that behaves like a UE toward its parent node, and a DU portion that behaves like a base station toward the next-hop IAB node.

[0022] The term "terminal device" refers to any terminal device capable of wireless communication. As an example and not a limitation, a terminal device may also be referred to as a communication device, user equipment (UE), subscriber station (SS), portable subscriber station, mobile station (MS), or access terminal (AT). Terminal devices can include, but are not limited to, mobile phones, cellular phones, smartphones, Voice over IP (VoIP) phones, wireless local loop phones, tablets, wearable terminal devices, personal digital assistants (PDAs), portable computers, desktop computers, image capture terminal devices (such as digital cameras), gaming terminal devices, music storage and playback devices, in-vehicle wireless terminal devices, wireless endpoints, mobile stations, laptop embedded devices (LEEs), laptop devices (LMEs), USB dongles, smart devices, wireless customer premises equipment (CPEs), Internet of Things (IoT) devices, watches or other wearable devices, head-mounted displays (HMDs), vehicles, drones, medical devices and applications (e.g., remote surgery), industrial devices and applications (e.g., robots and / or other wireless devices operating in the context of industrial and / or automated processing chains), consumer electronics devices, devices operating on commercial and / or industrial wireless networks, etc. The terminal device may also correspond to the mobile terminal (MT) portion of an IAB node (e.g., a relay node). In the following description, the terms "terminal device," "communication device," "terminal," "user equipment," and "UE" are used interchangeably.

[0023] As used herein, the terms “resource,” “transmission resource,” “resource block,” “physical resource block” (PRB), “uplink resource,” or “downlink resource” can refer to any resource used to perform communication, such as communication between a terminal device and a network device, including resources in the time domain, frequency domain, spatial domain, code domain, or any other combination of time, frequency, spatial, and / or code domain resources used to implement communication. In the following, unless explicitly stated otherwise, resources in both the frequency and time domains will be used as examples of transmission resources used to describe some exemplary embodiments of this disclosure. Note that the exemplary embodiments of this disclosure are equally applicable to other resources in other domains.

[0024] Figure 1 An example communication environment 100 in which exemplary embodiments of the present disclosure may be implemented is shown. In the communication environment 100, a plurality of communication devices, including a first device 110 and a second device 120, can communicate with each other. The first device 110 may be a terminal device or a UE. The second device 120 may be a network device, a network node, a BS, a gNB, or an eNB. The first device 110 may communicate with the second device 120 within the coverage area of ​​a cell managed by the second device 120.

[0025] As used herein, the transmission direction from the second device 120 to the first device 110 is referred to as the downlink (DL), and the transmission direction from the first device 110 to the second device 120 is referred to as the uplink (UL).

[0026] It should be understood that Figure 1 The number of devices, equipment, and their connections shown is for illustrative purposes only and does not impose any limitations. Communication environment 100 may include any suitable number of devices configured to implement exemplary embodiments of this disclosure. Although not shown, it should be understood that one or more additional devices or equipment may be located in a cell, and one or more additional cells may be deployed in communication environment 100. For example, in Figure 1 The diagram depicts a terminal device; however, it should be understood that the communication environment 100 may include additional terminal devices besides those shown.

[0027] Communication in communication environment 100 can be implemented according to any suitable communication protocol(s), including but not limited to cellular communication protocols, wireless local area network communication protocols (such as IEEE 802.11, etc.), and / or any other currently known or future-developed protocols. Furthermore, communication can utilize any suitable wireless communication technology, including but not limited to: Code Division Multiple Access (CDMA), Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), Frequency Division Duplex (FDD), Time Division Duplex (TDD), Multiple-Input Multiple-Output (MIMO), Orthogonal Frequency Division Multiple Access (OFDM), Discrete Fourier Transform Extended OFDM (DFT-s-OFDM), and / or any other currently known or future-developed technologies. For example, new waveforms can be developed and adopted during runtime via artificial intelligence / machine learning (AI / ML) techniques.

[0028] Work within 3GPP has introduced advanced features aimed at improving mobility processes. Specifically, there are research projects focusing on Layer 1 (L1) / Layer 2 (L2) triggered mobility (LTM). Regarding LTM cell handover commands, the MAC layer specification defines the MAC CE frame, such as... Figure 2 As shown, it illustrates the LTM cell handover command MAC CE 200. The LTM cell handover command MAC CE 200 can include seven octet bytes (OCT). Each OCT can include one or more fields, such as... Figure 2As shown. For example, OCT3 may include a Reserved (R) field and a Transport Configuration Indicator (TCI) Status Identifier (ID) field. For inter-CU LTM features / functions, the source gNB sends a MAC CE cell handover command message to the UE, allowing the UE to select or derive the relevant session keys used for handover. In this context, session keys refer to those session keys used during key processing in the handover. For vertical key derivation, the next-hop chain counter (NCC) value needs to be signaled to the UE.

[0029] Figure 3 A schematic diagram of an LTM cell handover command MAC CE is shown, illustrating a potential method for transmitting NCC values ​​via the LTM cell handover command MAC CE frame. Figure 3 As shown, the NCC value is based on three binary digits. Specifically, Figure 2 The three (R) bits in the LTM cell handover command MAC CE 200 can be replaced by the NCC value. Figure 3 The structure shown is only one example; other placements of the NCC value are possible. However, this paper assumes that the MAC frame carries the NCC value. From a security perspective, MAC CE frames are unprotected. For example, there is no encryption, no integrity protection, and no replay protection. From a risk assessment perspective, because the NCC value is used to select the key further used to derive the session key, robust security mechanisms are required. Generally, MAC CE security solutions should be usable for different features. In other words, the security solution should be generic, and protection of the NCC value should be the first use case for the security solution.

[0030] To examine this more comprehensively at the entity level, the MAC layer framework should be considered, namely the MAC layer building blocks and the building blocks that primarily create / consume MAC CEs. Figure 4 An overview of the MAC architecture for the device is shown 400. As shown, multiple layers, such as upper and lower layers, can be specified. Multiple channels and protocols can be configured for these channels. MAC CEs can be transmitted via control function blocks such as MAC layer control function blocks. MAC CE values ​​are created / consumed by MAC layer control function blocks. Various MAC CEs can be generated by... Figure 4 The MAC control function block shown is created or consumed.

[0031] First-level checks of the defined MAC CEs have shown that not all MAC CEs have the same sensitivity. Therefore, not all MAC CEs need to be protected in the same way. Thus, a potential solution should consider introducing MAC CE channels, where each channel provides a separate / different level of security. On the other hand, the transmission rate of MAC CEs is also a factor; some MAC CEs will be transmitted very frequently, while others will be transmitted infrequently. This is another reason for introducing MAC CE channels. MAC CE values ​​will be transmitted via transport blocks (TBs). This can be referenced... Figure 5A and Figure 5B To understand, Figure 5A and Figure 5B Example DL MAC PDU 500A and example UL MAC PDU 500B are shown. For DL ​​transmissions, MACCE frames will be included before the MAC CE SDU, while for UL transmissions, these will be appended after the MAC SDU. However, the MACCE framework is the same for both DL and UL, and this framework anticipates the use of both fixed-size and variable-size MAC CE SDUs. Therefore, depending on the format, the MAC CE subheader may or may not require a length value.

[0032] For security reasons, namely encryption and integrity protection, key derivation and keystream generation are required. Key derivation is used in the context of the key hierarchy defined by 3GPP, such as... Figure 6 As shown, it illustrates the key hierarchy generation process 600 in 5GS. Different keys (e.g., K) are obtained by running the Key Derivation Function (KDF). RRCint The KDF is placed within Radio Resource Control (RRC). The KDF will use different inputs to derive the output key. Keystream generation uses an algorithmic core (e.g., AES, Snow 5G, ZUC) and other relevant input parameters to compute the output keystream, which is then XORed with the plaintext input bitstream.

[0033] Keystream generation is essential for encryption (see...) Figure 7A It illustrates an example data encryption process 700A and integrity protection (see [reference]). Figure 7B The example derivation process shown in 700B for MAC-I / Non-Access Layer (NAS)-MAC (or XMAC-I / XNAS-MAC) is different. Figure 7AAs shown, on the sender's side, a plaintext block can be encrypted based on a keystream block to obtain a ciphertext block. The keystream block can be generated based on the key, count, bearer, direction, and length. On the receiver's side, a plaintext block can be obtained from the ciphertext block based on the keystream block. Similarly, a keystream block can be generated based on the key, count, bearer, direction, and length.

[0034] like Figure 7B As shown, on the sender side, MAC-I or NAS-MAC can be generated based on the key, count, message, direction, and bearer. On the receiver side, XMAC-I or XNAS-MAC can be obtained based on the key, count, message, direction, and bearer.

[0035] To gain a more comprehensive view at the system level, the end-to-end RAN / CN architecture should be considered. More specifically, the split-gNB should be considered more carefully, as the introduction of MAC CE security and key deployment adds new aspects. Figure 8 The protocol stack 800 for supporting RRC and NAS connections in IAB-MT is shown. It should be understood that, as Figure 8 The protocol stack 800 shown is for illustrative purposes only, and other deployments are possible. As illustrated, an IAB node such as IAB Node 2 (e.g., IAB-MT) can communicate with the AMF via the NAS layer. IAB Node 2 can communicate with IAB donors such as the CU via the RRC layer and the Packet Data Convergence Protocol (PDCP) layer. Furthermore, between IAB Node 2 and another IAB node such as IAB Node 1 (e.g., IAB-DU), the corresponding Radio Link Control (RLC), MAC, and Physical (PHY) layers are connected. MAC messages such as MAC CE can be transmitted between IAB Node 1 and IAB Node 2 via the MAC layer.

[0036] As described above, the KDF is mapped to the RRC, and the RRC in this deployment is mapped to the gNB-CU. The PDCP can be divided into PDCPc and PDCPu, and both handle decryption / encryption and / or integrity protection / authentication. There is no clear separation between them. The PDCP in this deployment is mapped to the gNB-CU. In this deployment, key derivation and keystream generation are always processed internally within the gNB-CU. The KgNB is always protected and maintained internally within the gNB-CU. Now, to introduce MAC CE security, it may be necessary to maintain the key material within the MAC layer of the gNB-DU.

[0037] Several challenges arise when extending security features to MAC CE at the MAC layer. For example, a suitable framework is needed to integrate security operations such as encryption and / or integrity protection into existing MAC CE mechanisms. A proper key derivation process is expected to provide the necessary keys for MAC CE protection. The generation and distribution of key streams used for MAC CE security should be carefully managed, especially in split-gNB or other complex network deployments. Furthermore, replay protection needs to be introduced for MAC CE frames to prevent malicious reuse of earlier transmissions.

[0038] According to some example embodiments of this disclosure, a solution for MAC CE security protection is provided. In the solution, a terminal device receives or transmits a MAC message including at least one MAC PDU. The at least one MAC PDU includes at least: a MAC CE SDU, and protection-related information of the MAC message. The MAC CE SDU includes a payload portion, and at least the MAC CE SDU and the protection-related information are protected for integrity. Therefore, the security of the MAC CE can be enhanced.

[0039] Figure 9 A flowchart of an example method 900 for implementing MAC CE security protection at a device according to some example embodiments of the present disclosure is shown. For discussion purposes, [the following will be discussed]. Figure 1 Method 900 is described from the perspective of the first device 110. It should be understood that method 900 can also be implemented by the second device 120.

[0040] At block 900, the first device 110 receives or transmits a MAC message including at least one MAC PDU. That is, the MAC message may include one or more MAC PDUs. At least one MAC PDU includes a first MAC PDU. The first MAC PDU includes at least a MAC CE SDU and protection-related information for the MAC message. In some example embodiments, the first MAC PDU may also include header information and a message authentication code, which may be referred to as MAC-I. The header information may be integrity-protected and / or encrypted, and the message authentication code may be unencrypted and not integrity-protected. The MAC CE SDU includes a payload portion, and at least the MAC CE SDU and the protection-related information are integrity-protected. In this way, the security of the MAC CE can be enhanced. As used herein, the device transmitting the MAC message may be referred to as the sender of the MAC message, and the device receiving the MAC message may be referred to as the receiver of the MAC message. If the first device 110 sends a MAC message, then the second device 120 may be the receiver of the MAC message. If the first device 110 receives a MAC message, then the second device 120 may be the sender of the MAC message. The MAC message may be generated by the sender. The information in a MAC message can be deduced or obtained by the receiver based on the format of the MAC message.

[0041] In some example embodiments, the protection-related information may include the security type of the MAC message. For example, the security type of the MAC message may include the SecTag type, which can be used for security algorithm selection.

[0042] In some example embodiments, protection-related information may include a channel identifier that indicates cryptographic protection and / or the sensitivity of the MAC message. The channel identifier may be referred to as a CID, and it can be used to select "yes / no" cryptographic protection, and also to indicate the sensitivity of the MAC CE frame. For example, if the channel identifier is less than a threshold, it can indicate that the MAC CE SDU is encrypted and protected for integrity; or, if the channel identifier is greater than or equal to the threshold, it can indicate that the MAC CE SDU is protected for integrity but not encrypted. That is, a smaller CID value can indicate a more sensitive MAC CE, while a larger value can be used for a lower sensitivity. Sensitivity can be compared to high sensitivity, which is both integrity and encryption, while lower sensitivity is only integrity.

[0043] In some example embodiments, protection-related information may include a MAC layer sequence number used for replay protection. This sequence number may be referred to as a SIN, and can be a MAC layer-specific sequence number used for replay protection.

[0044] In some example embodiments, protection-related information may include the length of the secure MAC CE in the MAC message. This value can be used to indicate the presence of a secure MAC CE frame. For example, if the length of the secure MAC CE is zero, it may indicate that a secure MAC CE does not exist in the MAC message; or, if the length of the secure MAC CE is greater than zero, it may indicate the size of the MAC CE SDU or the size of the secure MAC CE in the MAC message.

[0045] As described above, a MAC message may include multiple MAC PDUs. In some example embodiments, at least one MAC PDU may also include a second MAC PDU that is different from the first MAC PDU. For example, the second MAC PDU may be the last PDU in the MAC message, and the first MAC PDU may be placed before the second MAC PDU. In some example embodiments, the MAC CE SDU and the second MAC PDU may be protected for integrity. Additionally or alternatively, the MAC CE SDU and the second MAC PDU may be encrypted. The second MAC PDU may include at least one header and at least one MAC CE.

[0046] Reference Figure 10A and Figure 10B This will allow for a better understanding of the multiple security protection mechanisms for MAC CE presented in this article. Figure 10A An example MAC CE security framework 1000A according to some embodiments of this disclosure is shown. For example... Figure 10A As shown, a MAC message may include a single MAC PDU. A MAC PDU may include MAC CE SDU 1010, MAC-I 1020, and MACCE SecTag 1030. MAC-I 1020 may be referred to as the message authentication code and may not be protected by integrity. MAC CESDU 1010 may include information related to control elements and may be protected by integrity and optionally encrypted. In this case, protection is per MAC CE SDU, meaning that (multiple) protection mechanisms cover MAC CE SDU 1010.

[0047] MAC CE SecTag 1030 may include SecTag type 1031, Channel Identifier (CID) 1032, Sequence Number (SN) 1033, and / or Length Value 1034. In this document, MAC CE SecTag 1030 itself may be referred to as protection-related information. Furthermore, each or any combination of SecTag type 1031, CID 1032, SN 1033, and Length Value 1034 may be referred to as protection-related information. In some examples, SecTag 1030 may always be at the end. The receiver of the MAC message can obtain the information elements from a right-to-left relevance perspective. This arrangement allows future fields, such as SN 1033 or Length Value 1034, to be adapted to new requirements.

[0048] SecTag type 1031 can be used for security algorithm selection. CID 1032 can be used to select "yes / no" password protection and can also be used to indicate the sensitivity of the MAC CE frame. For example, a small CID value can indicate a more sensitive MAC CE, while a larger CID value can indicate a lower sensitivity. For example, a higher level of sensitivity may require both integrity protection and encryption, while a lower level of sensitivity may only require integrity protection. SN 1033 can be a MAC layer-specific sequence number and can be used for replay protection. Length value 1034 can be used to indicate the presence of a secure MAC CE frame. For example, if the length value 1034 is equal to zero, it can indicate that a secure MAC CE is not present; or if the length value 1034 is greater than zero, it can indicate the size of the secure MAC CE frame.

[0049] The MAC PDU may also include a subheader 1040. The subheader 1040 can also be protected for integrity. That is, the subheader 1040 can also be included in integrity protection. However, since the subheader 1040 does not contain confidential information, it can be unencrypted (although it can still be encrypted if needed). In this case, it is protected by encryption as per the MAC CE SDU and by integrity as per the MAC PDU.

[0050] Figure 10B Another example of a MAC CE security framework 1000B according to some embodiments of this disclosure is shown. For example... Figure 10B As shown, a MAC message can include three MAC PDUs 1001-1003 (instead of...). Figure 10A(A single MAC PDU in the context of the three MAC PDUs). The last of the three MAC PDUs, MAC CE PDU 1003, may include MAC-I 1020 and SecTag 1030. The other two PDUs (although they do not contain MAC-I 1020 or SecTag 1030) can still be protected for integrity and / or encryption under the same overall security mechanism. In this example, MAC CE PDU 1020 can be encrypted, while MAC CE PDUs 1001-1003 can be protected for integrity. Again, as mentioned above, subheading 1040 can also be encrypted if necessary. In this case, the protection is per MAC CE frame, meaning that this(multiple) protection mechanism covers the entire MAC CE frame as a whole.

[0051] The (multiple) designs also ensure that legacy devices (whether terminal or network devices) do not crash or fail upon receiving the proposed security features, even if they lack the ability to verify (multiple) enhanced protections. As mentioned above, a MAC frame may include a subheader and an associated MAC CE block. For backward compatibility purposes, the overall structure of the MAC frame remains unchanged. The MAC CE, which can have a fixed or variable size, still exists. The corresponding header remains as described above, and the existing (R)-bits are not used.

[0052] When a legacy device receives an integrity-protected MAC CE frame, it may be able to read and interpret the frame because the sub-header is not encrypted. Furthermore, since the MAC SDU immediately follows the sub-header, the legacy device may also be able to read and interpret the SDU. The legacy device may be able to read but not interpret the SecTag and MAC-I. In this case, the SecTag and MAC-I can be discarded by the legacy device. It can be seen that the (multiple) MAC CE frame design can be used for multicast / broadcast integrity-protected MAC CE frames, which can be read and interpreted by both legacy devices and other devices.

[0053] When a legacy device receives a MAC CE frame that is encrypted and protected for integrity, it may be able to read and interpret the frame because the subheading is not encrypted. However, subsequent information elements cannot be interpreted by the legacy device because they cannot be decrypted. In this case, the legacy device can discard all elements that cannot be interpreted.

[0054] This disclosure also provides several key derivation mechanisms for MAC CE security. In some example embodiments, a first key can be derived for the encryption portion of a MAC message, and a second key can be derived for the integrity protection portion of a MAC message. (See references) Figure 11A and Figure 11BThis allows for a better understanding of the proposed (multiple) key derivation mechanisms. Figure 11A and Figure 11B Two example procedures, 1100A and 1100B, are shown for key derivation used for MAC CE security protection. The first key may include key K. MACENC 1104, and the second key may include key K. MACINT 1103, such as Figure 11A and Figure 11B As shown.

[0055] Procedures 1100A and 1100B can represent the process for deriving key K. MACINT 1103 and K MACENC 1104 has two options. In the second option, represented by procedure 1100B, one can directly choose from K. gNB，NH Create key K in 1101 MACINT 1103 and K MACENC 1104. In the first option represented by process 1100A, it can be selected from key K. gNB，NH 1101 Create key K gNB-DU 1102, and then you can use the key K. gNB-DU 1102 to calculate key K MACINT 1103 and K MACENC 1104. This is understandable; the key K... gNB-DU 1102 is used as an example of a parameter that can be computed for each entity. In this example, the parameter is computed for DU. In another instance, a parameter can be computed for CU, and this parameter can be referred to as the key K. gNB-CU In some other examples, parameters can be computed for any other entity handling MAC CE security. For security reasons, K... gNB，NH 1102 may not be exposed outside its origin placement. Procedures 1100A and 1100B can be integrated into the key hierarchy generation procedure 600. For example, as Figure 6 The portion marked 610 shown (outlined by dashed lines) can be replaced by either process 1100A or process 1100B.

[0056] This disclosure also provides multiple keystream generation and distribution mechanisms for MAC CE security. Multiple keystream generation mechanisms for encryption are provided herein. In some example embodiments, the first device 110 may determine a counter value based on the MAC layer sequence number and the MAC superframe number (HFN). The first device 110 may determine the bearer based on the channel identifier. The first device 110 may determine the keystream based on the counter value, the bearer, and a first key. The first device 110 may encrypt the MAC CE SDU based on the keystream. The first device 110 may then transmit a MAC message to the second device 120.

[0057] refer to Figure 12A This allows for a better understanding of the various key stream generation mechanisms used for encryption. Figure 12A An example process 1200A for keystream generation for MAC CE security protection according to some embodiments of this disclosure is shown. Figure 12A As shown, the count value 1201 can be determined based on MAC HFN 1203 and SN 1033. The values ​​of MAC HFN 1203 and SN 1033 can be used for replay protection. Additionally, these two values ​​can be used for keystream revocation. The bearer 1202 can be determined based on CID 1032. As used herein, CID 1032 can be the same as the CID assigned by a lower layer, or it can be separate from the CID 1032 assigned by a lower layer. The count value 1201, bearer 1202, and K can be used as the basis for determination. MACENC 1104 determines the keystream. Then, the MAC CE SDU 1010 can be encrypted based on the keystream.

[0058] Additionally, this document provides several keystream generation mechanisms for integrity protection. In some example embodiments, the first device 110 may determine a count value based on the MAC layer sequence number and MAC HFN 1203. The first device 110 may determine the bearer based on the channel identifier. The first device 110 may determine the keystream based on the count value, the MAC CE frame, the bearer, and the second key. For example, a MAC-I may be generated. The first device 110 may then transmit a MAC message to the second device 120.

[0059] refer to Figure 12B This allows for a better understanding of the various keystream generation mechanisms used for integrity protection. Figure 12B An example process 1200B for keystream generation for MAC CE security protection according to some embodiments of this disclosure is shown. Figure 12B As shown, the count value 1201 can be determined based on MAC HFN 1203 and SN 1033. The values ​​of MAC HFN 1203 and SN 1033 can be used for replay protection. Additionally, these two values ​​can be used for key stream revocation. Bearer 1202 can be determined based on CID 1032. As used herein, CID 1032 can be the same as the CID assigned by a lower layer, or it can be separate from the CID 1032 assigned by a lower layer. The count value 1201, bearer 1202, MAC CE frame, and K... MACINT1103 determines the key stream. For example, MAC-I 1020 can be generated. Then, the first device 110 can transmit the MAC message to the second device 120. In this case, the complete MAC CE frame, except for MAC-I 1020, can be integrity protected.

[0060] This disclosure also provides (multiple) replay protection mechanisms for MAC CE security. In some example embodiments, the first device 110 may receive MAC messages from the second device 120 within a receiving window. The first device 110 may perform replay protection for the MAC messages based on the MAC layer sequence number included in protection-related information.

[0061] In some examples, replay protection can be provided at a higher layer. For replay protection, MACHFN 1203 and MAC SN 1033 can be used. The receiving side (e.g., first device 110) can span the receiving window and wait for a new MACCE frame. If the received MAC CE frame is within the window size, it will be used for further processing; otherwise, it will be discarded. In some examples, replay protection can be provided at the MAC layer. In this case, MAC SN 1033 can be used for replay protection. In some examples, replay protection can be provided using MAC CE-specific information elements. In the context of L1 / L2 triggered mobility, there are schemes to include the NCC value in the MAC CE cell handover command. In this case, this NCC value (currently 3 bits) can be used by the receiving entity to detect replay.

[0062] It should be understood that the methods and frame structures proposed in this paper for MAC CE security protection can be used for various types of MAC CE, including but not limited to: - Semi-persistent (SP) Channel State Information Reference Signal (CSI-RS) / Channel State Information Interference Measurement (CSI-IM) resource set activation / deactivation MAC CE; - Non-periodic CSI triggers state sub-selection MAC CE; - MAC CE activated / deactivated for the UE-specific Physical Downlink Shared Channel (PDSCH) Transport Configuration Indicator (TCI) status; - MAC CE for TCI status indication specific to the UE; -Activation / deactivation of MAC CE regarding SP CSI reports for the Physical Uplink Control Channel (PUCCH); - Activation / deactivation of MAC CE for the enhanced SP CSI report of PUCCH; -SP probe reference signal (SRS) activates / deactivates MAC CE; -PUCCH spatial relation activation / deactivation MAC CE; - Enhanced PUCCH spatial relation activation / deactivation MAC CE; -SP Zero Power (ZP) CSI-RS Resource Set Activation / Deactivation MAC CE; - Recommended bit rate MAC CE; - Enhanced SP / Aperiodic (AP) SRS Spatial Relationship Indicator MAC CE; -SRS path loss reference RS update MAC CE; -PUSCH path loss reference RS update MAC CE; - SRS spatial relationship indication MAC CE based on serving cell set; -SP locates SRS activation / deactivation MAC CE; -Timed incremental MAC CE; - Protection symbol MAC CE; - Positioning measurement gap activation / deactivation command MAC CE; -PPW activation / deactivation command MAC CE; -Activation / deactivation of MAC CE for PUCCH spatial relationships with PUCCH repetition in multiple transmit receiver points (TRP); - MAC CE update for PUCCH power control set updates for multiple TRP PUCCH repetitions; - Unify TCI status activation / deactivation of MAC CE; -Differential Koffset MAC CE; -Case-7 Timing advance offset MAC CE; -DL TX power adjustment MAC CE; - Sub-Integrated Access and Backhaul Distributed Unit (IAB-DU) Limited Beam Indicator MAC CE; - Timing status indicator MAC CE; - PSI-based SDU discard activation / deactivation MAC CE; - Beam Fault Detection Reference Signal (BFD-RS) indicates MAC CE; - Recommended beam indicator MAC CE for Integrated Access and Backhaul Mobile Terminal (IAB-MT); - Adjust MAC CE for the UL power spectral density (PSD) range for IAB; -Case-6 Timed Request MAC CE; - Network Controlled Repeater (NCR) Backhaul Link Beam Indicator (MAC CE); -NCR access link beam indicator MAC CE; - Enhanced unified TCI state activation / deactivation MAC CE; -LTM cell handover command MAC CE; - Candidate cell TCI status activation / deactivation MAC CE; - Aggregate SP to locate SRS activation / deactivation MAC CE.

[0063] In some example embodiments, the means capable of performing any of the methods 900 (e.g., Figure 1 The first device 110 or the second device 120 may include components for performing the corresponding operations of method 900. The device can be implemented in any suitable form. For example, the device can be implemented in a circuit system or a software module. The device can be implemented as or included in... Figure 1 In the first device 110 or the second device 120.

[0064] In some example embodiments, the apparatus includes components for receiving or transmitting MAC messages, the MAC messages including at least one MAC PDU. The at least one MAC PDU includes at least: a MAC CE SDU and protection-related information of the MAC message. The MAC CE SDU includes a payload portion, and at least the MAC CE SDU and the protection-related information are protected for integrity.

[0065] Figure 13 This is a simplified block diagram of a device 1300 suitable for implementing exemplary embodiments of the present disclosure. The device 1300 can be provided to implement a communication device, such as... Figure 1 The first device 110 or the second device 120 shown. As shown, the device 1300 includes one or more processors 1310, one or more memories 1320 coupled to the processors 1310, and one or more communication modules 1340 coupled to the processors 1310.

[0066] Communication module 1340 is used for bidirectional communication. Communication module 1340 has one or more communication interfaces to support communication with one or more other modules or devices. The communication interface can represent any interface necessary for communication with other network elements. In some example embodiments, communication module 1340 may include at least one antenna.

[0067] As a non-limiting example, processor 1310 can be any type suitable for a local technology network and can include one or more of the following: general-purpose computer, special-purpose computer, microprocessor, digital signal processor (DSP), and processor based on a multi-core processor architecture. Device 1300 can have multiple processors, such as application-specific integrated circuit chips, which are time-dependent on the clock of a synchronous main processor.

[0068] Memory 1320 may include one or more non-volatile memories and one or more volatile memories. Examples of non-volatile memories include, but are not limited to, read-only memory (ROM) 1324, electrically programmable read-only memory (EPROM), flash memory, hard disk, compact disc (CD), digital video disc (DVD), optical disc, laser disc, and other magnetic and / or optical storage. Examples of volatile memories include, but are not limited to, random access memory (RAM) 1322 and other volatile memories that do not retain data during power outages.

[0069] Computer program 1330 includes computer-executable instructions that are executed by an associated processor 1310. The instructions of program 1330 may include instructions for performing operations / actions of some example embodiments of this disclosure. Program 1330 may be stored in memory (e.g., ROM 1324). Processor 1310 can perform any suitable actions and processes by loading program 1330 into RAM 1322.

[0070] The exemplary embodiments of this disclosure can be implemented by program 1330, enabling device 1300 to execute as described in the reference. Figure 9 Any process discussed in this disclosure. Exemplary embodiments of this disclosure may also be implemented by hardware or a combination of software and hardware.

[0071] In some example embodiments, program 1330 may be tangibly contained in a computer-readable medium, which may be included in device 1300 (such as in memory 1320) or in other storage devices accessible by device 1300. Device 1300 may load program 1330 from the computer-readable medium into RAM 1322 for execution. In some example embodiments, the computer-readable medium may include any type of non-transitory storage medium, such as ROM, EPROM, flash memory, hard disk, CD, DVD, etc. As used herein, the term "non-transitory" is a limitation of the medium itself (i.e., tangible, not tactile), and not a limitation of the persistence of data storage (e.g., RAM versus ROM).

[0072] Figure 14An example of a computer-readable medium 1400 is shown, which may be in the form of a CD, DVD, or other optical storage disc. The computer-readable medium 1400 has a program 1330 stored thereon.

[0073] Generally, the various embodiments of this disclosure can be implemented in hardware or dedicated circuitry, software, logic, or any combination thereof. Some aspects can be implemented in hardware, and others can be implemented in firmware or software that can be executed by a controller, microprocessor, or other computing device. Although various aspects of the embodiments of this disclosure are shown and described as block diagrams, flowcharts, or using some other graphical representation, it should be understood that the blocks, apparatuses, systems, techniques, or methods described herein can be implemented in hardware, software, firmware, dedicated circuitry or logic, general-purpose hardware, or controllers or other computing devices, or some combination thereof, as non-limiting examples.

[0074] Some exemplary embodiments of this disclosure also provide at least one computer program product tangibly stored on a computer-readable medium, such as a non-transitory computer-readable medium. The computer program product includes computer-executable instructions that execute in a device on a target physical or virtual processor, such as those included in a program module, to perform any of the methods described above. Typically, a program module includes routines, programs, libraries, objects, classes, components, data structures, etc., that perform a particular task or implement a particular abstract data type. In various embodiments, the functionality of a program module can be combined or split among program modules as needed. The machine-executable instructions for a program module can execute within a local or distributed device. In a distributed device, the program module can reside on both local and remote storage media.

[0075] Program code used to perform the methods of this disclosure may be written in any combination of one or more programming languages. The program code may be provided to a processor or controller of a general-purpose computer, special-purpose computer, or other programmable data processing apparatus, such that, when executed by the processor or controller, the program code causes the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The program code may be executed entirely on a machine, partially on a machine, as a stand-alone software package, partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0076] In the context of this disclosure, computer program code or related data may be carried by any suitable carrier wave to enable a device, apparatus, or processor to perform the various processes and operations described above. Examples of carrier waves include signals, computer-readable media, etc.

[0077] Computer-readable media can be computer-readable signal media or computer-readable storage media. Computer-readable media can include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatuses, or devices, or any suitable combination thereof. More specific examples of computer-readable storage media will include electrical connections having one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable optical disc read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0078] Furthermore, although operations are described in a specific order, this should not be construed as requiring that such operations be performed in the specific order shown or sequentially, or requiring that all shown operations be performed to achieve the desired result. In some cases, multitasking and parallel processing may be advantageous. Similarly, although several specific implementation details are included in the above discussion, these should not be construed as limiting the scope of this disclosure, but rather as a description of features that may be specific to particular embodiments. Unless explicitly stated otherwise, certain features described in the context of a single embodiment may also be implemented in combination in a single embodiment. Conversely, unless explicitly stated otherwise, various features described in the context of a single embodiment may also be implemented individually or in any suitable sub-combination in multiple embodiments.

[0079] Although this disclosure has been described in language specific to structural features and / or methodological actions, it should be understood that the disclosure as defined in the appended claims is not necessarily limited to the specific features or actions described above. Rather, the specific features and actions described above are disclosed as exemplary forms for implementing the claims.

Claims

1. A device for communication, comprising: At least one processor; as well as At least one memory, the at least one memory storing instructions, the instructions causing the device to at least: Receive or transmit Media Access Control (MAC) messages, the MAC messages including at least one MAC Protocol Data Unit (PDU). The at least one MAC PDU includes at least: a MAC control element (CE) service data unit (SDU) and protection-related information of the MAC message. The MAC CE SDU includes a payload portion, and at least the MAC CE SDU and the protection-related information are protected for integrity.

2. The apparatus according to claim 1, wherein the protection-related information includes at least one of the following: The security type of the MAC message, A channel identifier, which indicates at least one of the cryptographic protection of the MAC message or the sensitivity of the MAC message. MAC layer sequence number used for replay protection, or The length of the secure MAC CE in the MAC message.

3. The apparatus of claim 2, wherein the zero length of the secure MAC CE indicates that there is no secure MAC CE in the MAC message, and / or The length of the secure MAC CE being greater than zero indicates the size of the MAC CE SDU or the size of the secure MAC CE in the MAC message.

4. The apparatus of claim 2, wherein the channel identifier being less than a threshold indicates that the MAC CE SDU is encrypted and protected for integrity, and / or The channel identifier being greater than or equal to the threshold indicates that the MAC CE SDU is protected for integrity and is not encrypted.

5. The apparatus of claim 1, wherein the at least one MAC PDU comprises the MAC PDU and at least one additional MAC PDU, and the MAC CE SDU and the at least one additional MAC PDU are protected for integrity and / or encrypted.

6. The apparatus of claim 5, wherein the at least one additional MAC PDU comprises at least one header and at least one MAC CE.

7. The apparatus of claim 5, wherein the MAC PDU is the last PDU in the MAC message.

8. The apparatus of claim 1, wherein the MAC PDU further includes header information and a message authentication code.

9. The apparatus of claim 8, wherein the header information is protected for integrity and / or encrypted, and The message authentication code mentioned therein is not encrypted and is not protected by integrity.

10. The apparatus of claim 1, wherein the first key is derived for the encrypted portion of the MAC message, and the second key is derived for the integrity protection portion of the MAC message.

11. The apparatus of claim 10, wherein the apparatus further causes: The count value is determined based on the MAC layer sequence number and the MAC superframe number HFN; The bearer is determined based on the channel identifier; The key stream is determined based on the count value, the bearer, and the first key; The MAC CE SDU is encrypted based on the key stream; as well as The MAC message is sent to another device.

12. The apparatus of claim 10, wherein the apparatus further causes: The count value is determined based on the MAC layer sequence number and the MAC superframe number HFN; The bearer is determined based on the channel identifier; The MAC message is generated based on the count value, the bearer, the second key, and the MAC CE frame, wherein the MAC CE frame does not include a message authentication code. as well as The MAC message is sent to another device.

13. The apparatus of claim 1, wherein the apparatus is further caused to: Receive the MAC message from another device within the receiving window; and Replay protection for the MAC message is performed based on the MAC layer sequence number included in the protection-related information.

14. The apparatus according to any one of claims 1 to 9, wherein the apparatus comprises a terminal device, the terminal device sending the MAC message to a network device or receiving the MAC message from a network device, or The device includes a network device that sends the MAC message to or receives the MAC message from the terminal device.

15. A method for communication, comprising: Receive or transmit Media Access Control (MAC) messages, the MAC messages including at least one MAC Protocol Data Unit (PDU). The at least one MAC PDU includes at least: a MAC control element (CE) service data unit (SDU) and protection-related information of the MAC message. The MAC CE SDU includes a payload portion, and at least the MAC CE SDU and the protection-related information are protected for integrity.

16. An apparatus for communication, comprising: A component for receiving or transmitting Media Access Control (MAC) messages, wherein the MAC message includes at least one MAC Protocol Data Unit (PDU). The at least one MAC PDU includes at least: a MAC control element (CE) service data unit (SDU) and protection-related information of the MAC message. The MAC CE SDU includes a payload portion, and at least the MAC CE SDU and the protection-related information are protected for integrity.

17. A computer-readable medium comprising instructions stored thereon for causing a device to perform at least the method according to claim 15.

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