A lightweight healable group key management method against clone attacks

Abstract

The application discloses a lightweight healable group key management method against clone attacks and relates to the field of unmanned aerial vehicle network security.The method comprises the following steps: each unmanned aerial vehicle generates a response by using a PUF function based on a challenge sent by a ground station to derive an encryption key, an encryption private key; a key intermediate material is calculated based on the private key of the unmanned aerial vehicle, and the private key and the key intermediate material are stored by using homomorphic encryption technology; a bidirectional hash chain is constructed, a group update key is calculated in combination with the change of unmanned aerial vehicles in the group, and a group key broadcast message is constructed; the private key is decrypted by the unmanned aerial vehicle, and the group update key is acquired based on the chained calculation relationship of the group key broadcast message and the bidirectional hash chain; when there is a communication interruption between the unmanned aerial vehicle and the ground station, self-healing is performed based on the group key broadcast messages before and after the interruption through the chained calculation relationship, or a mutual healing request with a signature is initiated to a neighbor unmanned aerial vehicle, so that a safe and efficient lightweight healable group key management method is provided.

Description

Technical Field

[0001] This invention belongs to the field of unmanned aerial vehicle (UAV) network security, specifically relating to a lightweight, healable group key management method resistant to cloning attacks. Background Technology

[0002] In recent years, unmanned aerial vehicles (UAVs) have been widely used in both military and civilian fields due to their advantages such as low cost, high mobility, and ease of operation. In many application scenarios, multiple UAVs, under the control of a ground control station (GCS), form a UAV network (UANET), sharing data in real time through group communication to efficiently complete tasks through swarm collaboration, which has become a mainstream trend. However, due to the openness of wireless channels, group communication in UAV networks is vulnerable to passive and active attacks such as eavesdropping and spoofing. To address this, the ground station typically distributes a group key, which each node uses to encrypt transmitted data, achieving secure information sharing within the group. Simultaneously, considering the dynamic joining and leaving of group members, the group key also needs to be dynamically updated to ensure forward and backward security of group communication. That is, newly joined UAVs cannot access previously communicated content, and departing UAVs cannot decrypt subsequent messages.

[0003] Compared to traditional wireless networks, UANET nodes are deployed in open environments, making them vulnerable to capture. This allows attackers to extract private keys stored internally by drones for device cloning, leading to group key leakage. Secondly, the high-speed movement of nodes and the highly dynamic changes in network topology within UANET cause intermittent interruptions in communication links between drones, resulting in frequent loss of group key broadcast messages. If drones cannot recover lost group keys, they will be unable to participate in mission collaboration. These factors present new problems and challenges for group key updates in drone networks.

[0004] To address these challenges, researchers have proposed a group key distribution method based on Physically Unclonable Functions (PUFs). The core idea is to leverage the unclonability, unpredictability, and tamper-proof properties of PUFs as device fingerprints to generate private keys for decrypting broadcast group key messages on demand, thus avoiding local storage of private keys and preventing cloning attacks. In addition, researchers have proposed a group key management method with healing capabilities. The core idea is to embed redundant information into broadcast messages, allowing legitimate group members to recover the lost group key using past and future broadcast messages after losing some broadcast messages (referred to as self-healing). Alternatively, members can actively request the lost group key from neighboring nodes (referred to as mutual healing). However, few studies have effectively combined these two approaches. Recently, Othman et al. proposed a healable group key distribution scheme (CPHKD) based on the Chinese Remainder Theorem and PUF (Othman W, Hong Z, Fuyou M, et al. CRT and PUF-based Self / Mutual-healing Key Distribution Protocol with Collusion Resistance and Revocation Capability[J]. IEEE Transactions on Mobile Computing, 2025:1-16. DOI:10.1109 / tmc.2025.3528491.), attempting to integrate PUF characteristics with the healable concept to address the dual challenges of UAV group key management. However, CPHKD still has the following shortcomings in terms of security and efficiency: (1) Insufficient security: First, the CPHKD scheme requires storing a large number of challenge-response pairs of group members in plaintext at the key management center, which poses a single point of leakage risk. Once the key management center is compromised, attackers may use modeling attacks to simulate the response generation mechanism of the PUF, thereby compromising its physical unclonability and ultimately enabling member cloning. Second, the group key mutual healing mechanism proposed in the CPHKD scheme lacks signature protection for key recovery materials, which allows attackers to forge group key broadcast messages, deceive mutual healing request nodes to recover fake group keys, and thus lead to the leakage of communication messages.

[0005] (2) Inefficiency: First, the CPHHD scheme requires the key management center to re-run the Chinese Remainder Theorem every time the group key is updated, which involves a large number of modular inverse operations, significantly increasing the group key distribution latency. Second, in order to achieve the self-healing capability of the group key in the CPHHD scheme, all historical group key broadcast messages need to be included in each broadcast message, which undoubtedly increases network communication linearly. Although the increased communication overhead can be mitigated by setting a sliding window (i.e., only saving a fixed number of historical group key broadcast messages within the window), this also limits the healing capability of the nodes.

[0006] Therefore, how to provide a secure, efficient, lightweight, and healable group key management method has become an important issue. Summary of the Invention

[0007] To address the aforementioned problems in the prior art, this invention provides a lightweight, healable group key management method resistant to cloning attacks.

[0008] The technical problem to be solved by this invention is achieved through the following technical solution: In a first aspect, the present invention provides a lightweight, healable group key management method resistant to cloning attacks, the lightweight, healable group key management method comprising: The ground station sends a challenge to all drones in the group; each drone generates a response based on the challenge using a PUF function to derive an encryption key, and uses the encryption key to encrypt its own private key; The ground station calculates the key intermediate material for each UAV based on the private keys of all UAVs using the Chinese Remainder Theorem, and uses homomorphic encryption technology to encrypt and store the private keys and key intermediate materials of each UAV. The ground station constructs a bidirectional hash chain; the bidirectional hash chain includes a forward hash chain and a backward hash chain; When a drone in the group changes, the ground station calculates the group update key based on the change and the bidirectional hash chain, and then constructs and sends a group key broadcast message based on the group update key, the encrypted private key of each drone, and key intermediate material. After receiving the group key broadcast message, each UAV calls its own PUF function to decrypt its own private key, and obtains the group update key based on the chain calculation relationship of the group key broadcast message and the bidirectional hash chain; When communication between a drone and the ground station is interrupted and a key update is lost, the group key is self-healed based on the group key broadcast messages before and after the interruption through the chained computation relationship of the bidirectional hash chain to recover the lost group key, or a signed mutual healing request is initiated to a neighboring drone to recover the lost group key.

[0009] Secondly, the present invention provides a lightweight, healable group key management system resistant to cloning attacks, the lightweight, healable group key management system comprising: The ground station is used to send challenges to all drones within the group; Each UAV is used to generate a response using a PUF function based on the challenge to derive an encryption key, and then uses the encryption key to encrypt its own private key. The ground station is also used to calculate the key intermediate material of each UAV based on the private keys of all UAVs using the Chinese Remainder Theorem, and to encrypt and store the private keys and key intermediate materials of each UAV using homomorphic encryption technology. The ground station is also used to construct a bidirectional hash chain; the bidirectional hash chain includes a forward hash chain and a backward hash chain; The ground station is also used to calculate the group update key based on the change and the bidirectional hash chain when a drone in the group changes, and to construct and send a group key broadcast message based on the group update key, the encrypted private key of each drone and key intermediate material. Each drone is also used to call its own PUF function to decrypt its own private key after receiving the group key broadcast message, so as to obtain the group update key based on the chain calculation relationship between the group key broadcast message and the bidirectional hash chain; For drones that lose key updates due to communication interruption with the ground station, the lost group key can be self-healed by using the chained computation relationship of the bidirectional hash chain based on the group key broadcast messages before and after the interruption, or a signed mutual healing request can be initiated to neighboring drones to recover the lost group key.

[0010] Thirdly, the present invention provides an electronic device, including a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus; Memory, used to store computer programs; When a processor executes a computer program stored in memory, it implements the steps of the method described in any of the above-described lightweight, healable group key management methods resistant to cloning attacks.

[0011] Fourthly, the present invention provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the method described in any of the above-described lightweight, healable group key management methods against cloning attacks.

[0012] This invention provides a lightweight, healable group key management method resistant to cloning attacks. It utilizes a PUF function to generate a response to derive an encryption key. Each UAV uses this encryption key to encrypt its own private key and stores it locally, eliminating the need to store the private key in plaintext on the UAV's local machine. This effectively avoids private key leakage and device cloning attacks caused by physical capture of the UAV. Simultaneously, the ground station employs homomorphic encryption technology to encrypt and store the private keys and key intermediate materials of each UAV, mitigating the risk of key leakage due to single points of failure and further enhancing system security.

[0013] Furthermore, during the mutual healing process, this invention employs a signed mutual healing request mechanism. Neighboring drones must verify the signature of the request message before responding, effectively preventing attackers from forging group key broadcast messages to deceive the mutual healing request node into restoring a fake group key and eliminating the risk of communication message leakage.

[0014] This invention establishes a chain-like computational relationship between group keys by constructing a bidirectional hash chain consisting of a forward hash chain and a backward hash chain. When communication between a UAV and the ground station is interrupted and group key updates are lost, the UAV can efficiently recover all lost group keys using the group key broadcast messages received before and after the interruption through the chain-like computational relationship of the bidirectional hash chain. This eliminates the need for the ground station to retransmit historical broadcast messages, significantly reducing communication overhead. Simultaneously, the UAV can also initiate mutual recovery requests to neighboring UAVs, quickly recovering lost keys using the latest group key broadcast messages held by neighboring UAVs, further improving the flexibility and efficiency of key recovery.

[0015] Homomorphic encryption technology is used to encrypt and store the private key and key intermediate materials, which significantly improves the efficiency of group key calculation while ensuring security. It is suitable for application scenarios where UAV network resources are limited and real-time requirements are high.

[0016] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0017] Figure 1 This is a flowchart illustrating a lightweight, healable group key management method against cloning attacks provided in an embodiment of the present invention. Figure 2 This is a schematic diagram of the unmanned aerial vehicle (UAV) network model provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of a bidirectional hash chain provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of group key update under case 1 provided in the embodiment of the present invention; Figure 5 This is a schematic diagram of group key update under scenario 2 provided in this embodiment of the invention; Figure 6 This is a schematic diagram of the group key self-healing process provided in an embodiment of the present invention; Figure 7 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0018] The present invention will be further described in detail below with reference to specific embodiments, but the implementation of the present invention is not limited thereto.

[0019] To address the issues of low security and poor efficiency in existing CPHKD methods, this invention provides a lightweight, healable group key management method resistant to cloning attacks. (See [link to relevant documentation]). Figure 1 , Figure 1 This is a flowchart illustrating a lightweight, healable group key management method against cloning attacks provided by an embodiment of the present invention, specifically including the following steps: In step S101, the ground station sends a challenge to all drones in the group; each drone generates a response based on the challenge using a PUF function to derive an encryption key, and uses the encryption key to encrypt its own private key.

[0020] See Figure 2 , Figure 2 This is a schematic diagram of a drone network model provided in an embodiment of the present invention. The drone network model consists of a ground station and multiple drones. The ground station is responsible for forming a group and dynamically updating the group key (GK) based on changes in members via a broadcast message (BM). Drones securely obtain the group key from the broadcast message to encrypt and share group messages. The first... The group key broadcast message for each round can be used express.

[0021] In this embodiment of the invention, the first ( The set of group members who participated in the session more than 0 times is denoted as The group key it uses is denoted as The broadcast message from the ground station distributing the group key is denoted as Meanwhile, considering the mobility of drones and external environmental interference, their communication link with GCS is unstable (i.e., intermittent), which can easily lead to the loss of group key update messages. For example, the... One drone In the The communication link with GCS was interrupted after the second group communication, and in the... l The communication link is restored after +1 group communication. Lost interval [ +1, The group key is updated within the GCS. The simplest method is to directly request the GCS to retransmit the lost group key, but this increases the communication bandwidth and computational cost of the nodes. Therefore, a secure and efficient group key repair mechanism needs to be designed based on group key management.

[0022] First, the ground station defines the system safety parameters. And select a hash function and a set of homomorphic encryption security parameters They are all random numbers of bits, among which This represents a binary string of arbitrary length. Then, the registration of the drone and the security protection of related key materials are completed.

[0023] Ground station selection challenge Send to all drones , For the total number of drones. When the... One drone Received challenge Then, firstly, it utilizes its own PUF function, denoted as... Received a response Derived encryption key .Then, Randomly select a large prime number of bits This serves as the private key for the drone to obtain subsequent group keys. Finally, Through secure channels (such as physical media) Send it back to the ground station, using an encryption key. And symmetric encryption algorithms (such as AES) Encrypt Saved locally.

[0024] In step S102, the ground station calculates the key intermediate material for each UAV based on the private keys of all UAVs using the Chinese Remainder Theorem, and uses homomorphic encryption technology to encrypt and store the private keys and key intermediate materials of each UAV.

[0025] In this embodiment of the invention, the ground station receives the private keys of all drones to obtain a private key set. Then, the intermediate key material for each UAV is calculated using the Chinese Remainder Theorem. First, the intermediate key material for the group is calculated. , of which Key intermediate material for a drone The calculation is as follows: ; in, Indicates process parameters; Indicates the first The private key of the drone; This indicates a modulo operation.

[0026] Secondly, the ground station selects a set of homomorphic encryption security parameters. Generate homomorphic encryption key ,in, The length is bits, and satisfying , and For position length Large prime numbers in bits for Bit length.

[0027] Then, the ground station uses a homomorphic encryption key and a symmetric homomorphic encryption algorithm to encrypt the private key set. and group key intermediate materials Encryption is performed to obtain a set of private encryption keys. and encrypted group key intermediate material Among them, the first The encrypted private key for each drone is , No. The encryption key intermediate material for each drone is ; Represents the encryption function for symmetric homomorphic encryption. This represents the homomorphic encryption key.

[0028] Finally, GCS will challenge The PUF function acting on itself receives its own response. And generate ground station encryption keys Simultaneously, it is encrypted using a symmetric encryption algorithm (such as AES) to obtain... Saved locally.

[0029] Step S103: The ground station constructs a bidirectional hash chain; the bidirectional hash chain includes a forward hash chain and a backward hash chain.

[0030] In this embodiment of the invention, the ground station constructs a bidirectional hash chain, including: The ground station selects the forward seed key and the backward seed key; Based on the forward seed key, a forward hash chain is obtained through iterative calculation of the hash function; Based on the backward seed key, a backward hash chain is obtained through iterative calculation of the hash function; A bidirectional hash chain is constructed based on a forward hash chain and a backward hash chain.

[0031] In this embodiment of the invention, the ground station selects a 2-bit seed key, which is denoted as the forward seed key. and backward seed key Then, based on the forward seed key and the backward seed key, construct a structure with a length of... A bidirectional hash chain, The value is the maximum number of conversation rounds in the group, see [link / reference]. Figure 3 , Figure 3 This is a schematic diagram of a bidirectional hash chain provided in an embodiment of the present invention. The bidirectional hash chain includes a forward hash chain and a backward hash chain.

[0032] Specifically, starting from the forward seed key, the hash function is iteratively calculated. For example, the forward hash value in the first round is... The forward hash value of the second round is Calculate up to the th The forward hash value of the round is This yields a forward hash chain; where For the first The forward hash value of the round. Starting from the backward seed key, the forward hash value of the round is calculated first. The backward hash value of the round is Continue iteratively calculating the hash function, such as the... The backward hash value of the round is , No. The backward hash value of the round is The backward hash value of the first round was calculated continuously. This yields a backward hash chain. This is the backward hash value from the second round; This represents a hash function.

[0033] At the same time, GCS uses a symmetric encryption algorithm to... Encryption is performed to obtain Stored locally in the backward hash chain Encrypting the back hash value yields... Saved locally.

[0034] Step S104: When a drone in the group changes, the ground station calculates the group update key based on the change and the bidirectional hash chain, and then constructs and sends a group key broadcast message based on the group update key, the encrypted private key of each drone, and the key intermediate material.

[0035] In this embodiment of the invention, a change in the drones within a group can refer to a drone joining the group or a drone leaving the group. Assume the first... Round group set denoted as , No. The set of drones that join in each round is denoted as , No. The departure of drones in rounds is denoted as At this point, after the group is changed, the first Round group collection for: ; To ensure forward / backward security of group communications, the ground station needs to implement the first... The specific process for updating the round group key is as follows: The ground station will face challenges Inputting a PUF function yields a response. And generate ground station encryption keys Used for decryption To recover the homomorphic encryption key At the same time, according to the first The drones in the round group set construct the first intermediate material for the group key broadcast message according to the following formula. Second intermediate material : ; in, This represents the decryption operation in a symmetric homomorphic encryption algorithm; Indicates the first Intermediate material for the encrypted group key of each round; Indicates the first The set of encrypted private keys for each round; and For homomorphically encrypted data, since homomorphic encryption technology is applied, the data can be summed directly without decryption. This greatly reduces the overhead required to decrypt and calculate after the encryption key is saved.

[0036] In this embodiment of the invention, when a drone within the group changes, the ground station calculates the group update key based on the change and a bidirectional hash chain, including: When the change is the first When only drones are added to the round group, the ground station determines the order based on the first drone in the forward hash chain. The forward hash value calculation of the round The forward hash value of each round, and the result is obtained based on the backward hash chain. The backward hash value of the round, using the first round The forward hash value of the round and the first The backward hash value of each round is used to calculate the group update key; When the change is the first When a drone leaves within a round group, a random number is selected instead of the first one. The forward hash value of each round, and the result is obtained based on the backward hash chain. The backward hash value of the round, using the replaced first... The forward hash value of the round and the first The backward hash value of each round is used to calculate the group update key.

[0037] In this embodiment of the invention, case 1 is when the first In each round, only drones join and no drones leave. See Figure 4 , Figure 4 This is a schematic diagram of group key update under scenario 1 provided in this embodiment of the invention. In this case, the ground station first authenticates the identity of the newly added drone and decrypts it. And calculate the first Forward hash value of round Distributed to drones via a secure channel, while the ground station generates encrypted data. Saved locally. Then, the ground station decrypts it. Obtain the backward hash chain value And select a random number. Calculate the group update key ; Modulus The multiplicative cyclic group.

[0038] Finally, the ground station generates a group key broadcast message based on the group update key, the encrypted private keys of each UAV, and key intermediate materials. Send to group , The calculation formula is as follows: ; in, Indicates the first Group update key for each round; Indicates the first The group key healing material of each round inherits its value directly from the first round. Group key healing materials in rounds ; Indicates the first Group key broadcast message signature for each round; To indicate the first The timestamp of the round; Indicates the first The forward hash chain key extracted from the group key healing material of each round is used to encrypt the update message.

[0039] Case 2 is when the first The drone leaves during a round, i.e. See Figure 5 , Figure 5This is a schematic diagram of group key update under scenario 2 provided in this embodiment of the invention. In this case, the ground station first authenticates the identity of the newly added drone and selects a random number. Replace the first in the forward hash chain The forward hash value of the round, that is, let Meanwhile, the ground station generates encrypted data. Saved locally. Then, the ground station decrypts it. Get the first Back hash chain value of the wheel At the same time, select a random number. Calculate the group update key .

[0040] Finally, the ground station generates a group key broadcast message. Send to group , The calculation formula is as follows: ; in, The value is determined by the first The forward hash value of each round is recalculated. Later added to the first The group key of the wheel is obtained after healing materials.

[0041] In step S105, after each UAV receives the group key broadcast message, it calls its own PUF function to decrypt its own private key and obtains the group update key based on the chain calculation relationship of the group key broadcast message and the bidirectional hash chain.

[0042] In this embodiment of the invention, after receiving the group key broadcast message, each UAV calls its own PUF function to decrypt its own private key, and obtains the group update key based on the chained computation relationship of the group key broadcast message and the bidirectional hash chain, including: After receiving the group key broadcast message, each drone will challenge its own PUF function to decrypt its own private key; Based on its own private key, the group key broadcast message is moduloed to extract the backward hash value of the current round; Determine the forward hash value for the current round based on the group key healing material status in the group key broadcast message; The group update key for the current round is calculated based on the forward hash value and the backward hash value of the current round.

[0043] In this embodiment of the invention, when the drone receives the group key broadcast message... hour, First check To judge Is it expired? Secondly, Challenge Enter its The function receives a response And generate Decrypt locally stored Get .Then, The current round, i.e., the [number]th round, is obtained through a single modular operation. Back hash value of round .at last, examine The update status is calculated using the following two methods to determine the group update key. .

[0044] In this embodiment of the invention, determining the forward hash value of the current round based on the group key healing material status in the group key broadcast message includes: If the group key healing material for the current round has not been updated, the drones newly added in the current round will use the forward hash value of the current round distributed by the ground station, while the existing drones will calculate the forward hash value of the current round based on the forward hash value of the previous round using a hash function. If the group key healing material for the current round has been updated, all drones extract the forward hash value for the current round from the group key healing material through modulo operation.

[0045] If the group key healing material for the current round has not been updated, i.e. when At that time, for Calculate group key ;for Decrypt first Get Then calculate the group key. Finally, regarding Encryption generation and Save locally, delete historical information and .

[0046] If the group key healing material for the current round has been updated, i.e. when hour, First, obtain the first modulo operation. Forward hash value of round Then calculate the group key. Finally, regarding Encryption generation and Save locally, delete historical information and .

[0047] Step S106: When there is a communication interruption between the UAV and the ground station and the loss of key update, the lost group key is recovered by self-healing through the chain calculation relationship of the group key broadcast messages before and after the interruption using a bidirectional hash chain, or a signed mutual recovery request is initiated to the neighboring UAV to recover the lost group key.

[0048] In this embodiment of the invention, the lost group key is recovered through self-healing based on the group key broadcast messages before and after the interruption, using a chain-like computation relationship of a bidirectional hash chain. This includes: The drone that experienced a communication interruption retrieves the last first group key broadcast message received before the interruption and the first second group key broadcast message received after communication was restored. Based on the first group key broadcast message and the second group key broadcast message, the group key lost during the communication interruption is recovered using the chain-like computation relationship of the bidirectional hash chain.

[0049] In this embodiment of the invention, the first One drone Passively waiting for the latest, i.e., the... First group key broadcast of the round And using it and the last received data before the link was interrupted, the first Second group key broadcast message of the round To calculate and recover all missed group keys, see [link / reference]. Figure 6 , Figure 6 This is a schematic diagram of the group key self-healing process provided in an embodiment of the present invention.

[0050] To restore the first Group key of the round For example, among which The specific process is as follows: First, the challenge Enter its The function receives a response And generate a key Decrypt locally stored Get .Then, The backward hash chain value is obtained through a single modulo operation. And use the chain-like computation relationship of the doubly hash chain to calculate The hash result is the back hash chain value. .

[0051] Then The group key is calculated as follows: forward hash chain value : If from the first The second group communication to the first No drones left during the subsequent group communications, meaning... The Middle Round-by-round forward hash chain key encryption update message .at this time, Calculate the first Forward hash value of round .

[0052] If the Rounds ( During communication, drones left, and distance Recently. At this time, From Extract the calculation of the first Round-by-round forward hash chain key encryption update message And calculate the first Forward hash value of round , and the Forward hash value of round .

[0053] at last, Recovering lost group keys .

[0054] In this embodiment of the invention, initiating a signed mutual recovery request to a neighboring drone to recover a lost group key includes: The drone that experiences a communication interruption constructs a mutual recovery request message and sends it to its neighboring drone; After receiving the mutual healing request message, the neighboring drone verifies the drone that experienced the communication interruption. If the verification is successful, and the current latest group key sequence number of the neighboring drone is greater than or equal to the sequence number in the mutual healing request message, the neighboring drone constructs a mutual healing response message and returns it to the drone that experienced the communication interruption. After receiving mutual recovery response messages from one or more neighboring drones, the drone that experienced the communication interruption sorts the messages according to the number of lost group keys carried in the mutual recovery response messages from most to least; and recovers the lost group key based on the mutual recovery response message with the most lost group keys.

[0055] In this embodiment of the invention, it is assumed that Neighbor drone collection ,in Indicates the spatial distance between two drones. For the one-on-one communication range of the drone, Indicates a neighbor's drone. When If a broadcast message is missed, it can proactively request a neighboring drone to retrieve the lost group key. The specific process is as follows: when When a group key is found to be lost (e.g., no group key update message has been received for a period of time), it constructs a mutual recovery request message. ,in for The most recently received group key broadcast message has the sequence number of , yes The corresponding timestamp refers to The local time when the mutual healing request message is initiated. Sign the message. This represents a hash-based message authentication code.

[0056] when The neighboring nodes, i.e., the neighboring drones (in the form of For example, suppose its latest group key sequence number is Received mutual healing request message Next, the drones that experienced communication interruptions were first verified, specifically by checking timestamps to ensure message freshness, and then... Decryption Get Group Key Verification is performed by calculating HMAC. After verification, The response will be handled in the following two ways.

[0057] 1) When hour, Constructing mutual healing response messages .in, express The number of lost group keys carried in the mutual healing response message. For the first Group key broadcast messages in rounds, for The corresponding timestamp, Sign the message.

[0058] 2) When When, it indicates There is also the possibility that the group key is lost, in which case it will not respond to the mutual healing request message, but instead start the mutual healing process with its neighboring drones.

[0059] Then, the lost group key recovery phase begins, during the mutual healing process. Multiple mutual healing response messages will be received, denoted as the mutual healing response message set. , First, check the timestamps in the mutual healing response message set and discard all expired mutual healing response messages; then, sort the remaining mutual healing response messages according to their timestamps. Sort the keys in descending order of size, and then recover all lost group keys using the following steps.

[0060] Step a, from Select The largest mutual healing response message utilizes a group key self-healing method. and First, restore the group key. .

[0061] Step b, Verify by calculating HMAC Once the verification is successful, Then, the group key self-healing method is used to utilize... and Recover all lost group keys If the verification fails, then Discard the message and select the second-longest. Repeat steps a and b in response messages until all lost group keys are correctly recovered.

[0062] Finally, mutual healing is confirmed. Construct message Send it to its neighboring drones to end this round of group key exchange. Among them... This is the current timestamp. To update the message signature.

[0063] In this embodiment of the invention, a PUF function is used to generate a response to derive an encryption key. Each UAV uses this encryption key to encrypt its own private key and stores it locally. This eliminates the need to store the private key in plaintext locally on the UAV, effectively preventing private key leakage and device cloning attacks caused by physical capture of the UAV. Simultaneously, the ground station employs homomorphic encryption technology to encrypt and store the private keys and key intermediate materials of each UAV, mitigating the risk of key leakage due to single point of failure and further enhancing system security.

[0064] Furthermore, during the mutual healing process, this invention employs a signed mutual healing request mechanism. Neighboring drones must verify the signature of the request message before responding, effectively preventing attackers from forging group key broadcast messages to deceive the mutual healing request node into restoring a fake group key and eliminating the risk of communication message leakage.

[0065] This invention establishes a chain-like computational relationship between group keys by constructing a bidirectional hash chain consisting of a forward hash chain and a backward hash chain. When communication between a UAV and the ground station is interrupted and group key updates are lost, the UAV can efficiently recover all lost group keys using the group key broadcast messages received before and after the interruption through the chain-like computational relationship of the bidirectional hash chain. This eliminates the need for the ground station to retransmit historical broadcast messages, significantly reducing communication overhead. Simultaneously, the UAV can also initiate mutual recovery requests to neighboring UAVs, quickly recovering lost keys using the latest group key broadcast messages held by neighboring UAVs, further improving the flexibility and efficiency of key recovery.

[0066] This invention uses homomorphic encryption technology to encrypt and store the private key and key intermediate materials. While ensuring security, it significantly improves the efficiency of group key calculation and is suitable for application scenarios where UAV network resources are limited and real-time requirements are high.

[0067] By combining the pre-computation concept and the Chinese Remainder Theorem, the group key is transformed into a solution of a set of congruence equations. When changes occur in drones within the group, the incremental update method effectively improves the efficiency of group key updates when cluster members change dynamically.

[0068] Based on the same inventive concept, embodiments of the present invention also provide a lightweight, healable group key management system resistant to cloning attacks. The lightweight, healable group key management system includes: The ground station is used to send challenges to all drones within the group; Each drone is used to generate a response based on a challenge using a PUF function to derive an encryption key, and then uses the encryption key to encrypt its own private key. The ground station is also used to calculate the key intermediate material of each UAV based on the private keys of all UAVs using the Chinese Remainder Theorem, and to encrypt and store the private keys and key intermediate materials of each UAV using homomorphic encryption technology. Ground stations are also used to build bidirectional hash chains; bidirectional hash chains include forward hash chains and backward hash chains. The ground station is also used to calculate the group update key based on the changes in the drones in the group, combined with the bidirectional hash chain, and to construct and send the group key broadcast message based on the group update key, the encrypted private keys of each drone, and the key intermediate material. Each drone is also used to call its own PUF function to decrypt its own private key after receiving the group key broadcast message, and to obtain the group update key based on the chain calculation relationship of the group key broadcast message and the bidirectional hash chain; For drones that lose key updates due to communication interruption with the ground station, the system can self-heal by using a chained computation relationship of a bidirectional hash chain based on the group key broadcast messages before and after the interruption to recover the lost group key, or initiate a signed mutual healing request to neighboring drones to recover the lost group key.

[0069] In this embodiment of the invention, a PUF function is used to generate a response to derive an encryption key. Each UAV uses this encryption key to encrypt its own private key and stores it locally. This eliminates the need to store the private key in plaintext locally on the UAV, effectively preventing private key leakage and device cloning attacks caused by physical capture of the UAV. Simultaneously, the ground station employs homomorphic encryption technology to encrypt and store the private keys and key intermediate materials of each UAV, mitigating the risk of key leakage due to single point of failure and further enhancing system security.

[0070] Furthermore, during the mutual healing process, this invention employs a signed mutual healing request mechanism. Neighboring drones must verify the signature of the request message before responding, effectively preventing attackers from forging group key broadcast messages to deceive the mutual healing request node into restoring a fake group key and eliminating the risk of communication message leakage.

[0071] This invention establishes a chain-like computational relationship between group keys by constructing a bidirectional hash chain consisting of a forward hash chain and a backward hash chain. When communication between a UAV and the ground station is interrupted and group key updates are lost, the UAV can efficiently recover all lost group keys using the group key broadcast messages received before and after the interruption through the chain-like computational relationship of the bidirectional hash chain. This eliminates the need for the ground station to retransmit historical broadcast messages, significantly reducing communication overhead. Simultaneously, the UAV can also initiate mutual recovery requests to neighboring UAVs, quickly recovering lost keys using the latest group key broadcast messages held by neighboring UAVs, further improving the flexibility and efficiency of key recovery.

[0072] This invention uses homomorphic encryption technology to encrypt and store the private key and key intermediate materials. While ensuring security, it significantly improves the efficiency of group key calculation and is suitable for application scenarios where UAV network resources are limited and real-time requirements are high.

[0073] This invention also provides an electronic device, such as... Figure 7 As shown, it includes a processor 701, a communication interface 702, a memory 703, and a communication bus 704, wherein the processor 701, the communication interface 702, and the memory 703 communicate with each other through the communication bus 704. Memory 703 is used to store computer programs; When the processor 701 executes the program stored in the memory 703, it implements the method steps of any of the above-mentioned lightweight healable group key management methods against cloning attacks.

[0074] The communication bus mentioned in the above electronic devices can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. This communication bus can be divided into address bus, data bus, control bus, etc. For ease of representation, only one thick line is used to represent it in the figure, but this does not indicate that there is only one bus or one type of bus.

[0075] The communication interface is used for communication between the aforementioned electronic devices and other devices.

[0076] The memory may include random access memory (RAM) or non-volatile memory (NVM), such as at least one disk storage device. Optionally, the memory may also be at least one storage device located remotely from the aforementioned processor.

[0077] The processors mentioned above can be general-purpose processors, including central processing units (CPUs), network processors (NPs), etc.; they can also be digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components.

[0078] The present invention also provides a computer-readable storage medium. A computer program is stored in the computer-readable storage medium, and when executed by a processor, the computer program implements the method steps of any of the above-described lightweight, healable group key management methods resistant to cloning attacks.

[0079] Optionally, the computer-readable storage medium may be non-volatile memory (NVM), such as at least one disk storage device.

[0080] Optionally, the aforementioned computer-readable storage medium may also be at least one storage device located remotely from the aforementioned processor.

[0081] In another embodiment of the present invention, a computer program product containing instructions is also provided, which, when run on a computer, causes the computer to perform the steps of the method described in any of the above-described lightweight, healable group key management methods against cloning attacks.

[0082] It should be noted that the terms "first," "second," etc., are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Rather, they are merely examples of systems and methods consistent with some aspects of the invention.

[0083] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Furthermore, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0084] Although the invention has been described herein in conjunction with various embodiments, those skilled in the art will understand and implement other variations of the disclosed embodiments by reviewing the accompanying drawings and the disclosure in carrying out the claimed invention. In the description of the invention, the word "comprising" does not exclude other components or steps, "a" or "an" does not exclude a plurality, and "a plurality" means two or more, unless otherwise explicitly specified. Furthermore, while different embodiments may describe certain measures, this does not mean that these measures cannot be combined to produce good results.

[0085] The method provided in this invention can be applied to electronic devices. Specifically, the electronic device can be a desktop computer, a portable computer, a smart mobile terminal, a server, etc. No limitation is made herein; any electronic device that can implement this invention falls within the protection scope of this invention.

[0086] For system / electronic device / storage medium embodiments, since they are basically similar to method embodiments, the description is relatively simple, and relevant parts can be referred to in the description of the method embodiments.

[0087] It should be noted that the system, electronic device, and storage medium in the embodiments of the present invention are respectively the system, electronic device, and storage medium applying the above-mentioned lightweight and healable group key management method against cloning attacks. Therefore, all embodiments of the above-mentioned lightweight and healable group key management method against cloning attacks are applicable to the system, electronic device, and storage medium, and can achieve the same or similar beneficial effects.

[0088] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A lightweight healable group key management method against clone attack, characterized in that, The lightweight, healable group key management method includes: The ground station sends a challenge to all drones in the group; each drone generates a response based on the challenge using a PUF function to derive an encryption key, and uses the encryption key to encrypt its own private key; The ground station calculates the key intermediate material for each UAV based on the private keys of all UAVs using the Chinese Remainder Theorem, and uses homomorphic encryption technology to encrypt and store the private keys and key intermediate materials of each UAV. The ground station constructs a bidirectional hash chain; the bidirectional hash chain includes a forward hash chain and a backward hash chain; When a drone in the group changes, the ground station calculates the group update key based on the change and the bidirectional hash chain, and then constructs and sends a group key broadcast message based on the group update key, the encrypted private key of each drone, and key intermediate material. After receiving the group key broadcast message, each UAV calls its own PUF function to decrypt its own private key, and obtains the group update key based on the chain calculation relationship of the group key broadcast message and the bidirectional hash chain; When communication between a drone and the ground station is interrupted and a key update is lost, the group key is self-healed based on the group key broadcast messages before and after the interruption through the chained computation relationship of the bidirectional hash chain to recover the lost group key, or a signed mutual healing request is initiated to a neighboring drone to recover the lost group key.

2. The lightweight healable group key management method of claim 1, wherein, The ground station constructs a bidirectional hash chain, including: The ground station selects a forward seed key and a backward seed key; Based on the aforementioned forward seed key, a forward hash chain is obtained through iterative calculation of the hash function; Based on the backward seed key, a backward hash chain is obtained through iterative calculation of the hash function; A bidirectional hash chain is constructed based on the forward hash chain and the backward hash chain.

3. The lightweight healable group key management method of claim 1, wherein, When a drone within the group changes, the ground station calculates the group update key based on the change and the bidirectional hash chain, including: When the change is the first When only drones are added to the round group, the ground station determines the order based on the first drone in the forward hash chain. The forward hash value calculation of the round The forward hash value of each round, and the result of the backward hash chain. The backward hash value of the round, using the first round The forward hash value of the round and the first The backward hash value of each round is used to calculate the group update key; When the change is the first When a drone leaves within a round group, a random number is selected instead of the first one. The forward hash value of each round, and the result of the backward hash chain. The backward hash value of the round, using the replaced first... The forward hash value of the round and the first The backward hash value of each round is used to calculate the group update key.

4. The lightweight, healable group key management method according to claim 1, characterized in that, After receiving the group key broadcast message, each drone calls its own PUF function to decrypt its own private key, and then obtains the group update key based on the chained computation relationship of the group key broadcast message and the bidirectional hash chain, including: After receiving the group key broadcast message, each drone inputs the challenge into its own PUF function to decrypt its own private key; Based on its own private key, the group key broadcast message is moduloed to extract the backward hash value of the current round; The forward hash value for the current round is determined based on the group key healing material status in the group key broadcast message; The group update key for the current round is calculated based on the forward hash value and the backward hash value of the current round.

5. The lightweight, healable group key management method according to claim 4, characterized in that, Based on the group key healing material status in the group key broadcast message, determine the forward hash value for the current round, including: If the group key healing material for the current round is not updated, the drones newly added in the current round will use the forward hash value of the current round distributed by the ground station, while the existing drones will calculate the forward hash value of the current round based on the forward hash value of the previous round using a hash function. If the group key healing material for the current round has been updated, all drones extract the forward hash value for the current round from the group key healing material through modulo operation.

6. The lightweight, healable group key management method according to claim 1, characterized in that, Based on the group key broadcast messages before and after the interruption, self-healing is performed through the chained computation relationship of the bidirectional hash chain to recover the lost group key, including: The drone that experienced a communication interruption retrieves the last first group key broadcast message received before the interruption and the first second group key broadcast message received after communication was restored. Based on the first group key broadcast message and the second group key broadcast message, the group key lost during the communication interruption is recovered using the chain-like calculation relationship of the bidirectional hash chain.

7. The lightweight, healable group key management method according to claim 1, characterized in that, Initiating a signed mutual heal request to neighboring drones to recover the lost group key includes: The drone that experiences a communication interruption constructs a mutual recovery request message and sends it to its neighboring drone; After receiving the mutual healing request message, the neighboring drone verifies the drone that experienced the communication interruption. If the verification is successful, and the current latest group key sequence number of the neighboring drone is greater than or equal to the sequence number in the mutual healing request message, the neighboring drone constructs a mutual healing response message and returns it to the drone that experienced the communication interruption. After receiving mutual recovery response messages from one or more of the neighboring drones, the drone that experienced the communication interruption sorts the messages according to the number of lost group keys carried in the mutual recovery response messages from most to least; and recovers the lost group keys based on the mutual recovery response message with the most lost group keys.

8. A lightweight, healable group key management system resistant to cloning attacks, characterized in that, The lightweight, healable group key management system includes: The ground station is used to send challenges to all drones within the group; Each UAV is used to generate a response using a PUF function based on the challenge to derive an encryption key, and then uses the encryption key to encrypt its own private key. The ground station is also used to calculate the key intermediate material of each UAV based on the private keys of all UAVs using the Chinese Remainder Theorem, and to encrypt and store the private keys and key intermediate materials of each UAV using homomorphic encryption technology. The ground station is also used to construct a bidirectional hash chain; the bidirectional hash chain includes a forward hash chain and a backward hash chain; The ground station is also used to calculate the group update key based on the change and the bidirectional hash chain when a drone in the group changes, and to construct and send a group key broadcast message based on the group update key, the encrypted private key of each drone and key intermediate material. Each drone is also used to call its own PUF function to decrypt its own private key after receiving the group key broadcast message, so as to obtain the group update key based on the chain calculation relationship between the group key broadcast message and the bidirectional hash chain; For drones that lose key updates due to communication interruption with the ground station, the lost group key can be self-healed by using the chained computation relationship of the bidirectional hash chain based on the group key broadcast messages before and after the interruption, or a signed mutual healing request can be initiated to neighboring drones to recover the lost group key.

9. An electronic device, characterized in that, It includes a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus; Memory, used to store computer programs; A processor, when executing a computer program stored in memory, implements the lightweight, healable group key management method against cloning attacks as described in any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the lightweight, healable group key management method against cloning attacks as described in any one of claims 1-7.

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