A method for managing group keys of a UAV self-organizing network supporting dynamic joining, leaving and key recovery of members

Abstract

The application discloses a kind of unmanned aerial vehicle self-organizing network group key management methods supporting member dynamic joining, quitting and key recovery, belongs to unmanned aerial vehicle self-organizing network security communication technical field.The method includes: system initialization;UAV node is registered, and based on physically unclonable function generation and equipment binding key material;Utilize Cuckoo filter to quickly screen legal members;Two-way authentication and key exchange process are executed between adjacent nodes and establish edge session key;Group key derivation is realized based on edge session key;When node is lost, group key recovery is executed;When member dynamic joins, quits or is revoked, group key update is executed.The method can reduce authentication and key management overhead, improve the processing efficiency when node recovery and member change, and ensure the forward security, backward security, integrity and confidentiality of group communication.

Description

Technical Field

[0001] This invention relates to the field of network security communication technology for unmanned aerial vehicles (UAVs), and specifically discloses a group key management method that supports dynamic joining, leaving and key recovery of members. Background Technology

[0002] A drone ad hoc network is a distributed network formed by multiple drones autonomously networking through wireless communication links. Compared with traditional mobile ad hoc networks, drone ad hoc networks are characterized by high node mobility, frequent network topology changes, easy interruption of communication links, and limited node resources. Therefore, they are widely used in scenarios such as disaster relief, regional inspection, collaborative reconnaissance, and formation flight.

[0003] In the aforementioned application scenarios, multiple drones typically need to perform collaborative tasks in a group, requiring nodes within the group to share state, transmit control commands, and exchange business data. To ensure the security of communication within the group, a group key is usually established among authorized members, and this key is used to implement message encryption, integrity protection, and member authentication. However, due to the continuous movement of nodes and frequent changes in link states in drone ad hoc networks, group members may dynamically join or leave, or even temporarily leave the current group due to link interruption and then re-enter the network, making group key management more complex than in traditional static network environments.

[0004] Most existing group key management schemes are designed for networks with relatively stable topologies, and often struggle to simultaneously address dynamic membership management and group communication continuity in UAV ad hoc networks. On one hand, when a new node joins the group or an existing node leaves, if the group key cannot be updated in a timely manner, backward and forward security cannot be guaranteed. On the other hand, when a legitimate node leaves the current group communication due to a short-term link interruption, if the entire group key negotiation process needs to be re-executed upon re-entry, it will incur significant communication and computational overhead, hindering the continuous execution of UAV group tasks.

[0005] Furthermore, in ad hoc drone networks, node devices typically have limited computing and storage capabilities. Directly employing group key management methods that rely on complex certificate verification, frequent public key calculations, or centralized key distribution can easily lead to high protocol overhead and increased node response latency, making it difficult to meet the real-time communication needs of drone swarms in highly dynamic scenarios. While some existing solutions can achieve node authentication or group key negotiation, they lack sufficient support for rapid member legitimacy verification in highly dynamic scenarios, low-overhead secure negotiation between adjacent nodes, group key recovery from lost nodes, and group key updates during dynamic member additions and removals.

[0006] Therefore, there is an urgent need for a group key management method suitable for UAV self-organizing networks, which can achieve rapid identification of legitimate members, secure negotiation between adjacent nodes, establishment of group keys, recovery of keys from lost nodes, and secure updates of group keys when members change dynamically, under conditions of high node mobility, rapid changes in network topology, and easy interruption of communication links, thereby improving the security, continuity, and efficiency of group communication. Summary of the Invention

[0007] To address the challenges in existing UAV ad hoc networks, such as high node mobility, rapid network topology changes, and easy communication link interruptions, group key management struggles to simultaneously manage dynamic member additions and removals, rapid reconnection of legitimate nodes after short-term disconnection, and the secure continuity of group communication. This invention provides a UAV ad hoc network group key management method that supports dynamic member additions and removals and key recovery, enabling secure establishment, updating, and recovery of group keys in highly dynamic scenarios.

[0008] To achieve the above objectives, the present invention adopts the following technical solution: This invention provides a method for managing group keys in a drone self-organizing network that supports dynamic member joining, leaving, and key recovery. It is applied to a drone self-organizing network consisting of a ground control station and multiple drone nodes, and includes the following process: First, the ground control station completes system initialization, generates system security parameters, constructs an elliptic curve cryptography environment, sets a hash function, initializes the cuckoo filter, and publishes system public parameters to the network.

[0009] Secondly, the drone nodes complete registration. The drone node generates a response to the input challenge based on a physically unclonable function, and generates key materials bound to the device based on the response, further generating a long-term private key and a long-term public key. The drone node sends its identity identifier and long-term public key to the ground control station. The ground control station generates a corresponding pseudo-identity identifier based on the identity identifier and long-term public key, writes the legitimacy index composed of the pseudo-identity identifier and long-term public key into the registry, and simultaneously inserts a cuckoo filter. The ground control station feeds back the pseudo-identity identifier to the drone node and distributes the cuckoo filter to registered drone nodes.

[0010] Then, the drone nodes participating in group key negotiation perform group discovery and member screening. The drone node broadcasts its own pseudo-identity and long-term public key; after receiving the broadcast information, the other drone nodes calculate the corresponding filter query fingerprint based on the pseudo-identity and long-term public key, and perform legitimate member screening on the broadcast node through the cuckoo filter; the nodes that pass the screening are added to the locally maintained ordered member set and form a logical ring according to the preset sorting rules of the long-term public key.

[0011] Based on this, each UAV node performs a two-way authentication and key exchange process with its predecessor and successor nodes in the logical ring, establishing a side session key with the predecessor node and a side session key with the successor node. During the two-way authentication and key exchange process, the initiating node generates temporary key parameters based on a physically non-cloning function and constructs an authentication request message using its long-term key material; the responding node verifies the authentication request message, calculates the side session key, and returns an authentication response message; the initiating node verifies the authentication response message and obtains a side session key consistent with that of the responding node, thus completing the secure negotiation between adjacent nodes.

[0012] After obtaining the side session keys with the predecessor node and the successor node, each UAV node performs group key negotiation. Specifically, each UAV node generates a local key contribution message and corresponding authentication tag based on its side session keys with the predecessor node, its side session keys with the successor node, and the current ordered member set, and broadcasts them to the group. After receiving the key contribution messages broadcast by other nodes in the group, each UAV node, based on the side session keys already established between itself and its neighboring nodes, gradually recovers the adjacent side session keys in logical ring order and verifies the authentication tags of each key contribution message step by step. After all key contribution messages have been verified, each UAV node calculates the global group key based on the recovered side session keys and the current ordered member set.

[0013] When a legitimate drone node exits the current group communication due to a communication link interruption and re-enters the network within a preset time window, group key recovery is performed. The target drone node selects an online legitimate drone node as the verification node based on its locally maintained ordered member set and initiates a group key recovery request to the verification node. The target drone node and the verification node re-perform the two-party authentication and key exchange process to establish a recovery session key. The verification node uses the recovery session key to encapsulate the current global group key and sends it to the target drone node. The target drone node uses the recovery session key to recover the current global group key, thereby rejoining the current group communication without re-performing the complete group key negotiation process.

[0014] When a new drone node joins the current group, the group key is updated as when a member joins. After the new drone node completes registration, it sends a join request to the legitimate drone nodes in the current group. After successful verification, a join session key is established between the new drone node and the verification node. Existing members in the group generate an updated group key based on the old group key, the updated ordered member set, and the group key update factor. The verification node sends a group key update message to the new drone node, enabling the new drone node to calculate the updated group key based on the join session key and the group key update message.

[0015] When a drone node is detected to have left the current group or been revoked, a group key update is performed. The drone node that has left or been revoked is removed from the current ordered member set, and an online node is selected from the remaining legitimate drone nodes as the processing node. The processing node generates a new group key update factor and updated member set information, constructs recovery items based on its directional shared values ​​with each of the remaining legitimate drone nodes, forms a leave update message, and sends it to the remaining legitimate members. Each remaining legitimate drone node recovers its group key update factor according to the leave update message, and calculates a new group key by combining the old group key, the group key update factor, and the updated member set information.

[0016] Compared with existing technologies, this invention uses physically unclonable functions to generate key materials bound to devices and combines them with a cuckoo filter to quickly screen legitimate members, reducing authentication overhead in highly dynamic scenarios while ensuring node identity security. It establishes side session keys through two-way authentication and key exchange between adjacent nodes, and completes group key negotiation based on these side session keys, improving the security and flexibility of group key establishment in UAV ad hoc networks. By setting a group key recovery mechanism, legitimate nodes can rejoin the current group communication without re-executing the complete group key negotiation process after a short period of disconnection, improving the continuity and recovery efficiency of group communication. Furthermore, by setting a group key update mechanism for dynamic member joining, leaving, or revocation, newly joined members can only obtain the updated group key, while leaving or revoked members cannot obtain subsequent group keys, thus ensuring backward and forward security of group communication. Therefore, this invention is well-suited to application scenarios in UAV ad hoc networks characterized by high node mobility, rapid network topology changes, and easily interrupted communication links, improving the security, continuity, and efficiency of group communication. Attached Figure Description

[0017] Figure 1 This is a system model diagram of the UAV self-organizing network in an embodiment of the present invention.

[0018] Figure 2 This is a flowchart of the group member discovery and logical loop construction in an embodiment of the present invention.

[0019] Figure 3 This is a flowchart of the two-party authentication and key exchange process in an embodiment of the present invention.

[0020] Figure 4 This is a flowchart illustrating the group key derivation process in an embodiment of the present invention. Detailed Implementation

[0021] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of protection of the present invention. In this embodiment, GCS represents a ground control station, UAV represents an unmanned aerial vehicle node, and VID... i UAV (Unmanned Aerial Vehicle) node i Identifier, PID i UAV (Unmanned Aerial Vehicle) node i The pseudo-identity identifier, C i L UAV (Unmanned Aerial Vehicle) node i The initial challenge generated during the registration phase, R i L Indicates the corresponding PUF response, sk i L UAV (Unmanned Aerial Vehicle) node i Long-term private key, PK i L UAV (Unmanned Aerial Vehicle) node i long-term public key, C i e UAV (Unmanned Aerial Vehicle) node i Temporary challenges arising during two-party authentication and key exchange, sk i e This represents the temporary private key, PK, derived from the temporary challenge. i e K represents the temporary public key derived from the temporary private key. i i+1 UAV (Unmanned Aerial Vehicle) node i Its successor node UAV i+1 Static shared values ​​between them, SEK i i+1 UAV (Unmanned Aerial Vehicle) node i Its successor node UAV i+1 The edge session key between them, SEK i i-1 UAV (Unmanned Aerial Vehicle) node i Its predecessor node UAV i-1 The edge session key between them, KCM i UAV (Unmanned Aerial Vehicle) node i Key contribution material broadcast during the group key derivation phase, State i UAV (Unmanned Aerial Vehicle) node i In the local state information during the two-party authentication and key exchange process, GK represents the current group session key. newGK represents the group key updated after a member joins. del This represents the updated group key after a member leaves or is revoked. PUF stands for Physically Unclonable Function, CF stands for Cuckoo Filter, H stands for Hash Function, and P stands for Elliptic Curve Base Point.

[0022] like Figure 1 As shown, the UAV self-organizing network in this embodiment includes a ground control station (GCS) and multiple UAV nodes. The GCS is used to complete system initialization, node registration, pseudo-identity generation, and maintenance of legitimate member information. The multiple UAV nodes form a UAV self-organizing network through wireless communication links. Legitimate UAV nodes form an ordered member set after member screening and form a logical ring according to a preset sorting rule of long-term public keys. Each UAV node performs two-way authentication and key exchange processes with its predecessor and successor nodes in the logical ring, establishes a side session key between adjacent nodes, and completes group key derivation, group key recovery, and group key update when members dynamically join, leave, or are revoked.

[0023] In this embodiment, the group key management method includes the following steps.

[0024] Step S1, System Initialization. The ground control station GCS first inputs the safety parameter κ, selects large prime numbers p and q of κ bits, and constructs the base field F. p The elliptic curve E is defined, and P is defined as the generator of the elliptic curve group. GCS further selects a hash function H in the elliptic curve cryptography environment and initializes the Cuckoo Filter CF, setting its fingerprint bit length to f. Subsequently, GCS publishes system public parameters par, which include p, q, E, P, the hash function set H, and relevant parameters of the Cuckoo Filter CF. To facilitate subsequent group discovery, member screening, two-party authentication and key exchange processes, and group key derivation, GCS also establishes a legitimate member registry during the system initialization phase. This registry records the identity identifier, pseudo-identity identifier, long-term public key, and legitimacy index information corresponding to the Cuckoo Filter for registered drone nodes. Through this initialization, subsequent drone nodes can complete node registration, legitimate member screening, two-party authentication and key exchange processes, and group key derivation under the same cryptographic parameters.

[0025] Step S2, Node Registration. Each UAV node... i A registration process is performed before connecting to the system. The UAV node to be registered... i Select a unique identifier (VID) iThen, an initial challenge C is randomly generated. i L The corresponding response R is obtained through the Physically Unclonable Function (PUF) within this node. i L Because the PUF output is tied to the physical characteristics of the device, it is difficult for different devices to replicate the same response. Therefore, this response can be used to generate long-term key material bound to the device. Specifically, this applies to UAV nodes. i According to response R i L and identity identifier VID i Generate a long-term private key sk using the hash function H. i L Then, using the long-term private key sk i L Generate a long-term public key PK from the elliptic curve base point P. i L Subsequently, the UAV node i Send a registration request message M to the ground control station GCS via a secure channel i The registration request message includes VID i and PK i L After receiving the registration request message, GCS selects a random number r. i And based on the identity identifier VID i Random variable r i PK with long-term public keys i L Generate the pseudo-identity PID corresponding to this drone node. i Subsequently, GCS uses the pseudo-identity PID... i PK with long-term public keys i L Construct query fingerprint f i and execute CF.Insert(f i The validity information corresponding to the node is written into the Cuckoo Filter CF. At the same time, GCS will... i PID i r i PK i L Write to the registry and send the PID via a secure channel. i Feedback to UAV nodes i UAV (Unmanned Aerial Vehicle) Node i Upon receiving the PID i Afterwards, secure storage { C iL PID i PK i L After all drones are registered, GCS securely writes the Cuckoo Filter into the drone nodes. In subsequent stages, all drones can use the Cuckoo Filter CF to perform a key-value pair (PK) operation on the long-term public key. i L The legitimacy of the document needs to be verified.

[0026] Step S3, as follows Figure 2 As shown, when multiple drone nodes need to form a security group, the first step is to perform group member discovery and logical ring construction. The drone nodes (UAVs) participating in group key negotiation... i First, the broadcasting member discovered message M. i 1 The member discovery message includes a pseudo-identity identifier (PID). i PK with long-term public keys i L After receiving the member discovery message, other drone nodes in the vicinity will form a set M of broadcast information from other participating nodes in the network. For each candidate node's broadcast item {PID} in set M... j PK j L The receiving node calculates the corresponding filter input fingerprint f. j * and call CF.Lookup(f j * The candidate node undergoes a rapid legitimate member screening. If the query result is 0, it indicates that the corresponding candidate node is not a legitimate member, and the receiving node immediately discards the member discovery message corresponding to that node and no longer includes it in this round of negotiation. If the query result is 1, it is considered a candidate member, and its broadcast information is retained for subsequent negotiations. For all nodes that pass the screening, the receiving node constructs a member set N including itself, and sorts it in ascending order according to the long-term public key lexicographical order to obtain an ordered sequence N'. The ordered sequence N' is used to determine the logical ring structure of this round of group key negotiation, so that each UAV node corresponds to a unique predecessor node and a unique successor node.

[0027] Step S4, as follows Figure 3As shown, each UAV node performs a two-way authentication and key exchange process with its predecessor and successor nodes to establish a side session key between adjacent nodes. After the logical ring is determined, each UAV node performs a two-way authentication and key exchange process with its predecessor and successor nodes to establish a side session key between adjacent nodes. The two-way authentication and key exchange process includes three parts: the initiating node sending an authentication request to the successor node, the node responding to the authentication request from the predecessor node, and the initiating node calculating the side session key after receiving the response message.

[0028] Specifically, any UAV node i When initiating, the first step is to challenge C locally over a long period of time. i L Recover long-term private key sk i L Subsequently, the initiator generated a temporary challenge C. i e And obtain the temporary private key sk based on the temporary challenge. i e PK with temporary public key i e Then, the initiator uses its own long-term private key sk i L Its successor node UAV i+1 Long-term public key PK i+1 L Calculate the static shared value K i i+1 To avoid directly exposing the temporary public key, the initiator performs a PK test on the temporary public key. i e Perform addition and blinding to obtain the blinded temporary public key CPK. i→i+1 e Next, the initiator obtains the current timestamp t1 and calculates the authentication code MAC. i 1 And construct the authentication request message M i 2 The authentication request message includes a PID. i CPK i→i+1 e t1 and MAC i 1 At the same time, the initiator will provide the intermediate state data (State) required for this round of interaction. i The side session key is cached locally so that it can be recovered from the response message later.

[0029] UAV responder i Upon receiving the predecessor node UAV i-1Authentication request message M sent i-1 2 Next, the validity of the timestamp t1 is verified; if the verification passes, then the long-term private key sk is used. i L PK with the long-term public key of the predecessor node i-1 L Calculate the static shared value K i i-1 And verify the authentication code MAC. i-1 1 If the authentication code is verified successfully, the temporary public key PK of the predecessor node is restored. i-1 e Then, the auxiliary parameters d1 and d2 are calculated. Subsequently, the responder uses its own temporary private key sk. i e , one's own long-term private key sk i L The recovered predecessor node temporary public key PK i-1 e and long-term public key PK of predecessor nodes i-1 L Calculate the protocol core value φ, and derive the side session key SEK from it. i i-1 Next, the responder further calculates the explicit confirmation tag Conf. i Get the current timestamp t2 and use the static shared value K i i-1 PK your own temporary public key i e Blinding is performed to obtain CPK. i→i-1 e Simultaneously calculate the response authentication code (MAC). i 2 Finally, the responder constructs the response message M. i 3 The response message includes a PID. i CPK i→i-1 e t2, MAC i 2 and Conf i The response message is then returned to the predecessor node, along with the side session key SEK. i i-1 Securely store and append static shared values ​​and temporary parameters to the State data. i This is for future use.

[0030] Initiator UAV iUpon receiving a UAV from the successor node i+1 response message M i+1 3 Next, the validity of timestamp t2 is verified. If the verification passes, the local cached state is retrieved. i Extracting static shared value K i i+1 It calculates the expected value of the authentication code, thereby affecting the MAC returned by subsequent nodes. i+1 2 Verification is performed. If the authentication code verification passes, the initiator restores the temporary public key PK of the successor node. i+1 e Calculate auxiliary parameters d1 and d2, and use your own temporary private key sk i e , one's own long-term private key sk i L Successor node temporary public key PK i+1 e And the long-term public key PK of the successor node i+1 L The core protocol value φ is obtained. Subsequently, the initiator derives the side session key SEK from the core protocol value. i i+1 And further calculate the expected confirmation label Conf i+1 * If Conf i+1 * With the acknowledgment tag Conf in the response message i+1 If they are the same, it means that the successor node has correctly obtained the same side session key as this node. The initiator accepts and securely stores the side session key SEK. i i+1 Otherwise, this round of negotiations will be terminated immediately. At this point, UAV... i The side session key negotiation with the successor node was completed. Subsequently, the UAV... i Erase local cached temporary state data. i And sensitive temporary quantities in volatile storage to enhance the forward security of the protocol.

[0031] Step S5, as follows Figure 4 As shown, after obtaining the adjacent edge session keys, each UAV node further executes the group key derivation process. After establishing the edge session keys with the predecessor and successor nodes, the UAV... i Two adjacent edge session keys SEK are already held. i i-1 and SEK i i+1To expand local pairwise keys into group session keys without adding extra broadcast rounds, UAV i First, based on the ordered node set N' obtained and stored during the group discovery phase, the current cluster topology digest h is calculated, and the member set and logical ring order of this round of negotiation are bound using the topology digest. Then, UAV... i Derive the local consistency check factor τ by combining the session keys from both sides i Lightweight key contribution material (KCM) is generated based on the side session key and topology digest. i The KCM i Used to transfer UAV i The session key between the UAV and its successor nodes is hidden beneath the session key shared with the predecessor node, thus ensuring that the contributed material is only meaningful to legitimate nodes capable of correctly recovering the adjacent keychain. Next, the UAV... i Obtain the current timestamp t3 and calculate the consistency authentication tag (Tag) for this contribution message. i Finally, UAV i Broadcast group key negotiation message M within the cluster i 4 The group key negotiation message includes a PID. i KCM i t3 and Tag i .

[0032] UAV i Receive UAV from all other nodes in the cluster j Broadcast message M j 4 Then, first process all received timestamps t3 j Perform freshness verification to defend against replay attacks. If all timestamps are valid, then the UAV... i The received broadcast messages are temporarily stored instead of being immediately verified across all messages. Instead, during subsequent key chain recovery, each newly recovered adjacent side session key is verified incrementally. Specifically, as key chain recovery progresses, the UAV... i Recovering a certain node UAV j After obtaining the session key between the node and its successor nodes, the consistency check factor τ corresponding to that node can be further calculated. j * And calculate the expected tag based on this. j * If the Tag is satisfied j * = Tag j This indicates that the node UAV jThe broadcast contribution material must be consistent with the session keys of its two adjacent sessions and must not have been tampered with during transmission; otherwise, the UAV... i The current key negotiation process is immediately determined to have been attacked and its execution terminated. Through this "recovery and verification on the go" mechanism, any forged or tampered contribution messages will be gradually detected during the key chain recovery process, thereby preventing erroneous contributions from continuously propagating along the ring.

[0033] After passing timestamp verification and consistency verification, UAV i By utilizing the adjacency relationships within the logical ring, the session key chain corresponding to each edge on the logical ring is recursively recovered, starting from the successor node. Subsequently, the UAV... i The group session key GK is generated based on the recovered session keys of all adjacent edges and the ordered set of nodes N'. The session key chains corresponding to the contribution materials of each legitimate node on the logical ring can be sequentially recovered and then hashed together with the topology digest h to obtain the current group session key GK. Since GK depends on the logical ring structure, the session keys of adjacent edges, and the set of valid members in this round, only drone nodes that have passed the legitimate member screening and correctly participated in this round of negotiation can obtain the correct GK.

[0034] Step S6, Group Key Recovery. During the operation of a UAV mission, some UAVs may temporarily lose connection and exit the current group communication. To address this, this implementation design includes a group key recovery mechanism, ensuring that legitimate but temporarily disconnected UAV nodes do not need to re-participate in the complete group session key negotiation process after reconnecting to the network.

[0035] When a target node UAV j After reconnecting within a preset time window, it first uses a locally maintained ordered set N' to determine the successor candidate node in the logical ring, and then attempts to send a message containing its own long-term public key PK to that candidate node. j L The group key recovery request. If the candidate node's response times out or verification cannot be completed due to physical link unreachability, then the UAV... j Based on the ordered nature of the logical ring, recursively try the next candidate node until a valid online verification node (UAV) is found. i Verification Node UAV i Upon receiving the request message, first confirm the UAV. j Long-term public key PK j L It does indeed exist in a locally maintained ordered set. Subsequently, the verification node UAV... i Re-execute with UAV j The two-party authentication and key exchange process, to UAVj Send an authentication request message and cache the state data locally. i .

[0036] UAV j Upon receiving the authentication request message, the same response process as the protocol is invoked to obtain message M. j and local state data j At the same time, the negotiated side session key SEK i j Secure storage. Next, UAV. i Received from UAV j After receiving the response message, the process of receiving the response and calculating the key is invoked to complete the verification and obtain the key matching the UAV. j Shared side session key SEK i j Subsequently, UAV i The current group session key GK is XORed with the session key to obtain the encrypted group key CGK, and the authentication code MAC is calculated. i Finally, UAV i Send recovery message to UAV j UAV j After verifying the validity of the received recovery message, the negotiated session key SEK is used. i j Recover the group key and store it securely. At this point, the UAV... j Reacquire the current group key without re-engaging in full group negotiation.

[0037] Step S7: Group key update upon member joining. During task execution, some UAVs may be recalled due to power depletion or other reasons, while backup UAVs are launched and join the current group. The group key needs to be updated when a new member joins.

[0038] UAVs for equipment k It was deployed into the air and connected to the existing ad hoc network. (UAV) k First, obtain the set of neighboring nodes within the current one-hop range by listening to the beacon. Then, make a targeted request to one of the legitimate group member nodes and send it a message containing its own long-term public key (PK). k L The request to join. Let UAV... i As a backup UAV k A legitimate verifier. UAV i First, retrieve the locally maintained cuckoo filter to verify the UAV. kThe system verifies the validity of the public key and invokes the initiation process during the two-party authentication and key exchange to obtain intermediate messages and status data, which are then sent to the UAV. k Send a message containing its own pseudo-identity PID. i The blinded temporary public key, timestamp, authentication code, and its own long-term public key PK i L The verification message is processed, and the local state data is cached simultaneously. i .

[0039] UAV k Received the verification message and public key PK i L Then, the response process during the two-party authentication and key exchange is invoked to obtain the temporary state data (State). k The side session key between the verifier and the verifier, and the message M to be returned. k UAV k Message M k Return to UAV i And securely store the session key for this round. Subsequently, the UAV... i Upon receiving message M k Then, the process of receiving the response and calculating the key is invoked to obtain the key corresponding to the UAV. k Consistent session key SEK i k Thus far, UAV i With UAV k A two-party authentication and key exchange process was completed between them.

[0040] After the session is established, UAV i The edge session key is used as the local shared key for the current member joining event, and a new update factor h is calculated based on the updated member set and the original group session key. new Existing legitimate members are determined based on the old group session key GK and the updated ordered member set N'. new and group key update factor h new Generate updated group session key GK new We can first adjust the old group key GK and the group key update factor h. new Perform a hash operation, then compare the updated member set digest with h. new Perform a hash operation and XOR the two hash results to obtain GK. new Verification Node UAV i According to the joining process, to UAV k Send Group Key Update Message (KCM) newThe UAV k Based on the session key SEK i k Group Key Update Message (KCM) new Recover or calculate the group key update factor h new And further calculate the updated group session key GK new Through the above-described update process, newly joined members will only receive the updated GK. new However, it cannot obtain the old group key before the update, thus ensuring backward security.

[0041] Step S8, Group Key Update When a Member Leaves or is Revoked. When a drone node is detected to have left the current group or been revoked, this implementation performs the group key update process upon member departure or revocation. First, the drone node that has left or been revoked is removed from the current ordered member set, forming the updated member set N'. del Subsequently, an online node is selected from the remaining legitimate drone nodes as the processing node. The processing node generates a new group key update factor h. del It constructs recovery items based on the directional shared values ​​between itself and each of the remaining legitimate drone nodes, forms an exit update message, and sends it to the remaining legitimate members.

[0042] Processing node and any remaining legitimate UAV node m Directed shared value DS between m It can be composed of the long-term private key of the processing node, the long-term public key of the corresponding remaining legitimate nodes, and the pseudo-identity identifier (PID) of the processing node. p And the corresponding PID of the remaining legitimate nodes m The hash operation is performed by all nodes. Then, the processing nodes construct a recovery item (Item) for each of the remaining valid nodes. m Specifically, the group key update factor h can be adjusted. del With the directed shared value DS m The updated member set N' del The collection summary and the exit update phase timestamp t del The jointly derived hash results are XORed to obtain the recovered item. m The processing node sends an exit update message, including the updated membership set information, timestamps, and all restored items, to the remaining legitimate members.

[0043] After receiving the exit update message, each remaining legitimate drone node calculates the same directed shared value DS using its own long-term private key and the long-term public key of the processing node. m and using the directional shared value DS mRecovery group key update factor h del Then, each remaining legitimate member updates the group key according to the old group key GK and the group key update factor h. del And the updated member set N' del Calculate the new group key GK del Specifically, the old group key GK and the group key update factor h can be used. del The updated member set digest is used together with the hash function to obtain the new group key GK. del Since the drone node that has exited or been revoked is no longer in the updated member set and cannot obtain a valid recovery item from the exit update message, it cannot obtain the updated new group key, thus ensuring forward security.

[0044] In this embodiment, the Cuckoo Filter (CF) is used to perform rapid legitimacy screening on candidate members to reduce unnecessary cryptographic operations; the Physically Unclonable Function (PUF) is used to generate key material bound to the device to improve the anti-copying capability of node identity and key material; the Logical Ring is used to organize legitimate members in the ordered member set, enabling each node to establish a side session key with its predecessor and successor nodes respectively; the side session key is used for subsequent group key derivation, group key recovery, and group key update when members dynamically join, leave, or are revoked.

[0045] It should be noted that, without departing from the basic concept of this invention, the specific implementation methods of the ground control station GCS in generating pseudo-identity identifiers (PIDs), forming ordered member sets, selecting verification nodes or processing nodes, constructing group key update messages, and generating recovery items can all be appropriately adjusted; the authentication message format, confirmation tag form, and specific derivation form of the side session key in the two-party authentication and key exchange process can also be equivalently replaced according to the actual application environment; the above equivalent replacements and improvements should all fall within the protection scope of this invention.

Claims

1. A method for managing group keys in a drone self-organizing network that supports dynamic member joining, leaving, and key recovery, characterized in that, The process includes the following steps: S1, System Initialization: The ground control station (GCS) generates system security parameters, constructs an elliptic curve cryptography environment, sets a hash function, initializes the Cuckoo Filter, and publishes system public parameters; S2, Node Registration: The UAV node generates a response to the input challenge based on the Physically Unclonable Function (PUF), and generates key materials bound to the device based on the response, further generating a long-term private key and a long-term public key; The UAV node sends its identity identifier and long-term public key to the ground control station (GCS). The ground control station (GCS) generates a corresponding pseudo-identity identifier (PID) based on the identity identifier and long-term public key, and writes the validity index composed of the pseudo-identity identifier (PID) and long-term public key into the registry, while simultaneously inserting the Cuckoo Filter; The ground control station (GCS) feeds back the pseudo-identity identifier (PID) to the UAV node and registers the Cuckoo Filter. S3, Group Discovery and Member Screening: UAVs participating in group key negotiation broadcast their pseudo-identity PID and long-term public key; after receiving the broadcast information from other UAVs, each UAV calculates the corresponding filter query fingerprint based on the pseudo-identity PID and long-term public key, and performs legitimate member screening on the broadcasting nodes through the Cuckoo Filter; the nodes that pass the screening are added to the locally maintained ordered member set, and a logical ring is formed according to the preset sorting rules of the long-term public key; S4, Side Session Key Establishment: each UAV performs two-party authentication and key exchange processes with its predecessor node and successor node in the logical ring, respectively, to establish a side session key with the predecessor node and a side session key with the successor node; S5, Group Key Negotiation: Each UAV node generates a local key contribution message and corresponding authentication tag based on its side session key with the predecessor node, its side session key with the successor node, and the current ordered member set, and broadcasts it to the group; after receiving the key contribution messages broadcast by other nodes in the group, each UAV node gradually recovers the adjacent side session keys according to the logical ring order based on the side session keys established between itself and its neighboring nodes, and gradually verifies the authentication tags of each key contribution message; after all key contribution messages are verified, each UAV node calculates the global group key GK based on the recovered side session keys and the current ordered member set; S6, Group Key Recovery: When the target UAV node exits the current group communication due to communication link interruption and re-enters the network within a preset time window, the target UAV node calculates the global group key GK based on the... The locally maintained ordered member set selects an online legitimate drone node as the verification node and initiates a group key recovery request to the verification node; the target drone node UAV and the verification node perform a two-party authentication and key exchange process again to establish a recovery session key. The verification node uses the recovery session key to encapsulate the current global group key GK and sends it to the target drone node UAV. The target drone node UAV uses the recovery session key to recover the current global group key GK; S7, group key update when a member joins: After the newly joined drone node UAV completes registration, it initiates a join request to the legitimate drone nodes UAV in the current group; after successful verification, a join session key is established between the newly joined drone node UAV and the verification node, and the original members in the group generate an updated group key based on the old group key, the updated ordered member set, and the group key update factor; The verification node sends a group key update message to the newly joined UAV node, enabling the newly joined UAV node to calculate the updated group key based on the joining session key and the group key update message. S8, Group key update when a member leaves or is revoked: When it is detected that a UAV node has left the current group or has been revoked, the UAV node is removed from the current ordered member set, and an online node is selected as the processing node from the remaining legitimate UAV nodes; the processing node generates a new group key update factor and updated member set information, constructs recovery items based on its directional shared values ​​with each of the remaining legitimate UAV nodes, forms a leave update message, and sends it to the remaining legitimate members; Each remaining legitimate UAV node restores the group key update factor according to the exit update message, and calculates a new group key by combining the old group key, the group key update factor, and the updated membership set information.

2. The group key management method according to claim 1, characterized in that, In step S2, the UAV node generates a response value to the challenge based on PUF, and generates a long-term private key through hash operation based on the response value and identity identifier, and then generates a long-term public key based on the long-term private key and elliptic curve generator.

3. The group key management method according to claim 1, characterized in that, In step S2, the ground control station GCS generates the pseudo-identity identifier PID using a random variable, an identity identifier, and a long-term public key. Based on the pseudo-identity identifier PID and the long-term public key, it generates a Cuckoo Filter query fingerprint and inserts the query fingerprint into the Cuckoo Filter so that subsequent UAV nodes can perform rapid legitimacy screening on candidate members.

4. The group key management method according to claim 1, characterized in that, In step S4, when any UAV node acts as the initiator, it generates a temporary private key and a temporary public key based on PUF, calculates a static shared value by combining its long-term private key with the target node's long-term public key, performs blinding processing on the temporary public key, and generates an authentication request message. When any UAV node acts as the responder, after verifying the timestamp and authentication code of the authentication request message, it restores the initiator's temporary public key, calculates the protocol core value, generates a side session key and an acknowledgment tag, and returns an authentication response message. After the initiator verifies the authentication response message, it obtains a side session key consistent with that of the responder.

5. The group key management method according to claim 1, characterized in that, In step S5, each UAV node generates local consistency verification information, local key contribution message and corresponding authentication tag based on its side session key with the predecessor node, its side session key with the successor node and the current ordered member set, and then broadcasts them.

6. The group key management method according to claim 5, characterized in that, In step S5, each UAV node performs stepwise consistency verification on the key contribution messages broadcast within the group in the logical ring order; only when the key contribution messages of all nodes pass the stepwise consistency verification will the result of this round of group key negotiation be accepted and the global group key GK be calculated.

7. The group key management method according to claim 1, characterized in that, In step S6, when the target UAV node recovers the group key, it prioritizes selecting the online legitimate UAV node UAV in the successor direction of the logical ring as the verification node based on the locally maintained ordered member set; if the current candidate verification node is unreachable or the response times out, it continues to select the next candidate UAV node UAV as the verification node along the logical ring sequence.

8. The group key management method according to claim 1, characterized in that, In step S7, after the existing members of the group confirm that the long-term public key of the newly added UAV node is valid, they insert the long-term public key of the newly added UAV node into the updated ordered member set, and generate an updated group key based on the old group key, the updated ordered member set, and the joining session key between the existing members and the newly added UAV node. The verification node further generates recovery material for the newly joined UAV node based on the updated group key and the joining session key, so that the newly joined UAV node can recover the updated group key.

9. The group key management method according to claim 1, characterized in that, In step S8, the processing node constructs a corresponding recovery item for each remaining legitimate UAV node. The recovery item is generated by the directional shared value between the processing node and the corresponding remaining legitimate UAV node, the exit node pseudo-identity identifier PID, the processing node pseudo-identity identifier PID, the corresponding remaining legitimate UAV node pseudo-identity identifier PID, the updated member set information, and the timestamp. Each remaining legitimate UAV node calculates the same directional shared value as the processing node using its own long-term private key and the processing node's long-term public key, and recovers the group key update factor based on the directional shared value.

10. The group key management method according to claim 1, characterized in that, In step S8, the processing node uses the old group key before exiting to encrypt and protect the message body in the exit update message, and adds an integrity verification tag to the outer broadcast message; after verifying the validity of the integrity verification tag and timestamp, each remaining legitimate UAV node first uses the old group key to decrypt the message body, then extracts its own recovery item from it, and calculates a new group key in combination with the recovered group key update factor.

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