Extensible unmanned aerial vehicle Internet of Things authentication key negotiation method

Abstract

The invention relates to the technical field of unmanned aerial vehicle network information security, in particular to an expandable unmanned aerial vehicle Internet of Things authentication key negotiation method, which comprises the following steps: initializing system parameters, and completing base station authorization and user registration; responding to successful user login and sending a request message, and sending the first encrypted request message to the key base station; the key base station sends the connection request to a base station corresponding to each unmanned aerial vehicle; each base station sends the second encryption request message to the target unmanned aerial vehicle; each target unmanned aerial vehicle determines a secret message and sends the secret message to the key base station; the key base station determines a target session message and a target secret message, sends the target session message to each target unmanned aerial vehicle, and sends the target secret message to the user; and each target unmanned aerial vehicle determines a target session key based on the target session message, and the user determines the target session key based on the target secret message. According to the invention, security negotiation of the session key between the user and the unmanned aerial vehicle can be realized, and the base station is effectively kept secret.

Description

Technical Field

[0001] The present invention relates to the field of drone network information security technology, and in particular to an extensible drone Internet of Things authentication key negotiation method. Background Art

[0002] Drone swarms excel in information collection and mission execution, but establishing secure communications between drones and remote users still faces major challenges. Before large-scale deployment, the following issues must be addressed: First, industrial drones that rely on wireless communications are vulnerable to malicious activities, including eavesdropping, interception, and replay attacks, and the confidentiality and integrity of messages need to be ensured; second, the rapid growth in the number of drone connections and the diverse needs of emerging drone services have put forward requirements for the scalability and flexibility of drone network security solutions.

[0003] Unlike traditional IoT networks, information leakage in the industrial field may lead to significant economic losses, and intercepted messages may cause drones to crash in industrial infrastructure areas, causing serious security issues. Therefore, industrial drone networks have more stringent requirements for confidentiality, integrity, and performance efficiency. One of the important security solutions is the authenticated key negotiation scheme, which negotiates session keys while authenticating remote users and drones to resist malicious attacks.

[0004] As drone clusters expand and the number of connections increases, users access data from multiple drones more frequently and need to negotiate different session keys for each drone. However, the traditional one-to-one AKA scheme requires re-authentication of users and base stations for each new connection, which leads to redundant computation and communication costs, exacerbating processing delays and bandwidth shortages. Existing scalable AKA schemes aim to negotiate multiple session keys through a single request and aggregate different session keys of multiple drones with the assistance of a trusted authority. However, temporary secret information needs to be aggregated by a trusted authority, which means that subsequent session keys will be disclosed to the base station, thereby endangering the security of the industrial drone network. When the intermediate base station is responsible for aggregating the drone's reply, the temporary random number used to form the session key needs to be calculated in plain text, which causes the session key to be disclosed to the base station, which may leak critical industrial data to third-party operators during subsequent data transmission. However, in real-world scenarios, the intermediate base stations managed by telecom operators cannot be considered completely trustworthy. It is necessary to protect high-value industrial data from semi-honest base stations. The session key between the drone and the remote user should be kept confidential from the intermediate base station. Therefore, a user-drone session key negotiation method that can effectively keep the base station confidential is urgently needed. Summary of the invention

[0005] To this end, the present invention provides a scalable UAV Internet of Things authentication key negotiation method to overcome the problem in the prior art that the session key between the user and the UAV cannot be kept confidential from the base station.

[0006] To achieve the above object, the present invention provides a scalable UAV Internet of Things authentication key negotiation method, comprising:

[0007] Step S1, initialize system parameters through the key management center, complete base station authorization and user registration, and perform mutual authentication between the base station and each drone;

[0008] Step S2, in response to the user successfully logging in and sending a request message for establishing a connection request with several target drones in the target drone list, determining a first encrypted request message based on the temporary session key, and sending the first encrypted request message to a key base station; the key base station is a base station closest to the user;

[0009] Step S3, the key base station decrypts the first encrypted request message based on the temporary session key and verifies the user identity. If the identity verification is successful, the key base station sends a connection request containing several target drones to the base stations corresponding to the drones.

[0010] Step S4, each base station searches whether there is any target drone in its corresponding airspace, and if so, determines a second encrypted request message based on the drone identity corresponding to the target drone, and sends the second encrypted request message to the target drone;

[0011] Step S5, each of the target drones determines its corresponding secret message based on the second encryption request message, and encrypts the secret message and sends it to the key base station;

[0012] Step S6, the key base station determines a target session message and a target secret message based on the Chinese remainder theorem and the secret message, and sends the target session message to each target drone, and sends the target secret message to the user;

[0013] In step S7, each of the target drones determines a target session key based on the target session message, and the user determines a target session key based on the target secret message.

[0014] Furthermore, in the step S1, the initializing system parameters includes:

[0015] Step S11, defining system parameters and secure hash function;

[0016] Step S12, determining an additive cyclic group and its corresponding generator based on an elliptic curve over a finite field, randomly selecting a secret integer from the multiplication group of integers modulo q corresponding to the large prime order q of the generator, and determining a secret public key corresponding to the secret integer;

[0017] Step S13, storing the secret integer and publishing each system parameter.

[0018] Further, in the step S1, the base station authorization includes:

[0019] The key management center assigns a corresponding base station identity to each base station, generates a base station private key and a base station public key corresponding to each base station identity, initializes a permissioned blockchain, defines a calling function, and registers the base station as a node in the permissioned blockchain.

[0020] Furthermore, in the step S1, the user registration includes:

[0021] Step S14: the user selects a user password and randomly selects a random number from the integer modulo q multiplication group as a first random number, generates a corresponding user device identity and a verification password hash value, and sends the user device identity and the verification password hash value to the key management center;

[0022] Step S15, the key management center randomly selects a random number from the integer modulo q multiplication group as a security parameter, and determines a shared secret message and a hidden secret message based on the security parameter and the user equipment identity;

[0023] Step S16: The user activates the device based on the first random number and the user password, and randomly selects a random number from the integer modulo q multiplication group as the second random number to generate a corresponding verification device hash value.

[0024] Furthermore, in step S1, the mutual authentication between the base station and each drone includes:

[0025] Step S17, the key management center randomly selects a number of random numbers from the integer modulo q multiplication group as the drone identity corresponding to each drone, determines the corresponding drone characteristics according to each drone identity, generates the corresponding pseudo drone identity, challenge and synchronization challenge, sends the drone identity, pseudo drone identity, challenge and synchronization challenge to the corresponding drone, and stores the drone identity and drone characteristics corresponding to each drone in the local database of the key management center;

[0026] Step S18, each drone determines a challenge response corresponding to each challenge and a synchronous challenge response corresponding to each synchronous challenge based on a physical non-cloning function, and sends the drone identity, challenge response and synchronous challenge response corresponding to each drone to a key management center;

[0027] Step S19, the key management center determines the challenge key, challenge reconstruction parameter, synchronous challenge key and synchronous challenge reconstruction parameter corresponding to each challenge response and synchronous challenge response based on the fuzzy extractor, and returns them to the corresponding drone and base station.

[0028] Furthermore, in the step S2, it includes:

[0029] Step S21, the user inputs the user device identity and the user password to the device to log in, determines the login password hash value and the login device hash value, and determines whether the user input matches based on the comparison result of the login device hash value and the verification device hash value. If they match, the user logs in successfully;

[0030] Step S22, the user randomly selects a random number from the integer modulo q multiplication group as a third random number, and determines a temporary private key and a temporary public key based on the shared secret information and the third random number;

[0031] Step S23, determining a temporary session key based on the temporary private key and the base station public key, encrypting the user pseudonym, the target drone identity, and the authentication hash based on the temporary session key to obtain a first encryption formula, and determining a first message hash digest based on the user pseudonym, the target drone identity, the authentication hash, and the first current timestamp;

[0032] Step S24: determine a first encryption request message based on the temporary public key, the first encryption formula, the first current timestamp and the first message hash digest, and send the first encryption request message to the key base station.

[0033] Furthermore, in the step S3, it includes:

[0034] Step S31, after receiving the first encryption request message, the key base station determines whether the first current timestamp meets a first determination condition, and if so, determines a temporary session key based on the temporary public key and the base station private key;

[0035] Step S32, decrypting the encrypted user pseudonym, target drone identity and authentication hash based on the temporary session key, and verifying the user identity. If the identity verification is successful, the key base station sends a connection request containing several target drones to the permission blockchain, and the permission blockchain sends the connection request to the base station corresponding to each drone;

[0036] The verification of the user identity includes verifying the first message hash digest and verifying the authentication hash.

[0037] Furthermore, in the step S4, it includes:

[0038] Step S41, after receiving the connection request, each base station searches whether there is each target drone in its corresponding airspace. If yes, it determines it as the target base station and retrieves the corresponding drone identity from the local database, and determines its corresponding pseudo drone identity, challenge and challenge key;

[0039] Step S42, the target base station generates a second current timestamp and randomly selects a random number from the integer modulo q multiplication group as a fourth random number, and hides the user identity and the fourth random number based on the challenge key to obtain a hidden user identity and a hidden fourth random number;

[0040] Step S43, determining a second message hash digest based on the temporary public key, the hidden fourth random number, the challenge, the user identity, the fourth random number, and the second current timestamp, and determining a second encryption request message;

[0041] Step S44: The target base station sends the second encryption request message and the temporary public key to the corresponding target drone.

[0042] Furthermore, in the step S5, it includes:

[0043] Step S51, after receiving the second encryption request message, each of the target drones determines whether the second current timestamp satisfies a second determination condition, and if so, reconstructs a challenge key based on a corresponding challenge reconstruction parameter;

[0044] Step S52, each of the target drones recovers the user identity and the hidden fourth random number based on the challenge key, and verifies whether the second message hash digest matches, and if so, determines a new challenge and a new response;

[0045] Step S53, each of the target drones randomly selects a random number from the integer modulo q multiplication group as a fifth random number and generates a random element, and encrypts the fifth random number based on the random element and the temporary public key to obtain a hidden fifth random number;

[0046] Step S54, each of the target drones determines a second encryption formula based on the corresponding pseudo drone identity, the new response, and the hidden fifth random number, and determines a third message hash digest based on the second encryption formula, the pseudo drone identity, the new response, the hidden fifth random number, and the third current timestamp, and determines a secret message, and sends the secret message to the corresponding target base station;

[0047] Step S55: Each of the target base stations sends the secret message to the key base station.

[0048] Furthermore, in step S6, it includes:

[0049] Step S61, after receiving the secret message corresponding to each target drone, the key base station determines whether the third current timestamp satisfies the third determination condition, and if so, decrypts the second encryption formula based on the challenge key, and verifies whether the third message hash digest matches;

[0050] Step S62, if there is a match, the key base station updates a new challenge based on the fourth random number and the challenge key, updates the pseudo drone identity based on the pseudo drone identity and the challenge key, updates the challenge key and the reconstruction parameter based on the new response, and obtains a third encryption formula;

[0051] Step S63, the key base station processes the fifth random number corresponding to each of the target drones and the drone characteristics based on the Chinese remainder theorem to determine an aggregate random number;

[0052] Step S64, the key base station generates the fourth current timestamp and the fifth current timestamp, determines a session identifier based on the challenge key corresponding to each of the target drones and the fourth current timestamp, and hides the session identifier to obtain a hidden session identifier;

[0053] Step S65, the key base station determines a fourth message hash digest based on the third encryption formula, the hidden session identifier, the updated reconstruction parameter, and the fourth current timestamp, and determines a target session message, and sends the target session message to each drone;

[0054] Step S66, the key base station encrypts the aggregate random number based on the temporary session key to obtain an encrypted aggregate random number, and determines a fifth message hash digest based on the encrypted aggregate random number, the session identifier, the aggregate random number and the fifth current timestamp, and determines a target secret message;

[0055] Step S67: the key base station sends the target secret message to the user.

[0056] Compared with the prior art, the beneficial effect of the present invention is that the present invention initializes system parameters through the key management center, completes base station authorization and user registration, and performs mutual authentication between the base station and each drone, which can improve the security of communication. The centralized management of the key management center can improve the scalability of the system and facilitate flexible adjustment. By encrypting the user's request message based on the temporary session key, the security of the negotiation can be improved, ensuring that the key and the content of the request message are not stolen during the transmission process. By using the key base station to verify the user identity and sending the connection request to the base station corresponding to each drone, it is possible to effectively prevent illegal users from accessing the system. If a large number of users send connection requests to drones in different areas, the precise forwarding mechanism of the key base station can ensure that the request quickly and accurately reaches the base station where the target drone is located, accelerating the connection establishment process. Each base station retrieves whether there is any target drone in its corresponding airspace, which can improve the utilization rate of communication resources, determine the second encrypted request message based on the drone identity corresponding to the target drone, and send the second encrypted request message to the target drone, further improving the security of the session key negotiation process. Each target drone determines its corresponding secret message based on the second encryption request message, and encrypts the secret message and sends it to the key base station, which can effectively resist the threat of tampering after the device is captured and ensure the physical security of the device. The key base station determines the target session message and the target secret message based on the Chinese remainder theorem and the secret message, which can achieve efficient aggregation of multi-drone session keys and maintain lightweight computing and communication overhead in the face of rapidly growing connection requirements. Each target drone determines the target session key based on the target session message, and the user determines the target session key based on the target secret message, which can further improve the confidentiality of the session key and ensure that privacy-preserving session key negotiation can be performed even in the presence of curious relay base stations.

[0057] Furthermore, the present invention utilizes the homomorphic properties of elliptic curve encryption to ensure privacy protection during information transmission. By defining a secure hash function, it can be used to verify the integrity of a message to ensure that the message has not been tampered with during transmission. A secret integer is randomly selected from the integer modulo q multiplication group, utilizing the unpredictability of random numbers. The randomly generated secret integer is difficult to be guessed by an attacker, further enhancing the confidentiality of the system.

[0058] Furthermore, the present invention manages user communications through a base station and assists data users in establishing connections with drones, thereby ensuring the communication quality and security of communication content between users and drones, simplifying user operation procedures, and improving user experience.

[0059] Furthermore, the present invention lays the foundation for subsequent two-factor authentication by combining the user password and the user device identity, increasing the difficulty for attackers to crack identity authentication. By generating and sending the verification password hash value instead of directly sending the user password, the anti-collision property of the hash function ensures that different passwords are unlikely to generate the same hash value, further enhancing the accuracy and security of password verification.

[0060] Furthermore, the present invention can protect the physical security of drones and prevent attackers from capturing drones and tampering with them by introducing physical unclonable functions and fuzzy extractors in the authentication process through the interaction between the key management center and the drones. By generating pseudo drone identities, challenges, and synchronization challenges corresponding to each drone, the problem of asynchrony between the base station and the drone can be solved.

[0061] Furthermore, the present invention determines a temporary session key based on a temporary private key and a base station public key, and utilizes the characteristics of asymmetric encryption to negotiate a symmetric temporary session key without relying on a pre-shared key, thereby improving the security and flexibility of communications. By encrypting the user pseudonym, the target drone identity, and the authentication hash to obtain the first encryption formula, the confidentiality of these sensitive information during transmission can be ensured.

[0062] Furthermore, the present invention can avoid replay attacks and improve system security and communication integrity by determining whether the first current timestamp satisfies the first determination condition. The key base station determines the temporary session key based on the same principle as the sender (temporary public key and base station private key), ensuring that the same key is used for communication with the sender to prevent data from being tampered with or stolen.

[0063] Furthermore, the present invention determines the pseudo drone identity for the target drone through the base station, provides a layer of protection for the real identity of the drone, determines the challenge and challenge key, introduces a challenge-response authentication mechanism, increases the complexity and reliability of authentication, and improves the system's ability to resist illegal drone access. The user identity is hidden based on the challenge key, so that the user identity is effectively protected during the transmission process.

[0064] Furthermore, the present invention ensures the timeliness of the received message by determining whether the second current timestamp satisfies the second determination condition, thereby avoiding replay attacks and improving system security and communication integrity. Reconstructing the challenge key based on the challenge reconstruction parameter, thereby restoring the user identity and hiding the fourth random number, and verifying whether the second message hash digest matches, can effectively prevent data leakage and illegal access, and implement a more powerful two-way authentication mechanism, which not only verifies the legitimacy of the user, but also proves its own legitimacy to the user. By determining new challenges and new responses, it increases the difficulty for attackers to crack the authentication process, making the authentication process more secure and reliable, and adapting to the ever-changing security threat environment.

[0065] Furthermore, the present invention ensures the timeliness of the received message by determining whether the third current timestamp satisfies the third determination condition, can avoid replay attacks, and improve system security and communication integrity. By aggregating the fifth random number and drone features corresponding to each target drone during the session through the Chinese remainder theorem, it is possible to achieve effective integration of multiple drone-related data and reduce the amount of data processing. The session identifier is determined based on the challenge key corresponding to each target drone and the fourth current timestamp. The confidentiality of the challenge key and the timeliness of the timestamp jointly guarantee the security of the session identifier. The challenge key is only known to authorized drones and key base stations, and the timestamp ensures that the session identifier is time-effective and difficult to be predicted or replayed by attackers. Hiding the session identifier further increases its confidentiality. Even if an attacker intercepts the communication data, it is difficult to obtain the real session identifier, thereby protecting the security and privacy of the session key negotiation process. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] Figure 1 This is a flow chart of an scalable UAV Internet of Things authentication key negotiation method according to an embodiment of the present invention;

[0067] Figure 2 This is a flow chart of the interaction between a user and a KMC during the user registration process of an embodiment of the present invention;

[0068] Figure 3 This is a flowchart of the interaction between the key management center and the drone according to an embodiment of the present invention;

[0069] Figure 4 The figure is a flow chart of authentication key negotiation between a user, a base station and a target UAV according to an embodiment of the present invention. DETAILED DESCRIPTION

[0070] In order to make the objects and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0071] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the protection scope of the present invention.

[0072] It should be noted that, in the description of the present invention, terms such as "up", "down", "left", "right", "inside" and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings. This is merely for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0073] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0074] The network architecture of the UAV Internet of Things consists of four main entities: the key management center KMC, M base stations BS k 、N UAVs j and a user U i , with the assistance of the base station, U i Ultimately, each UAV j Negotiate the target session key TSK ij , where k = 1, 2,…, M and j = 1, 2,…, N.

[0075] See also Figure 1 , Figure 4 As shown, Figure 1 This is a flow chart of an scalable UAV Internet of Things authentication key negotiation method according to an embodiment of the present invention; Figure 4 The following is a flowchart of the authentication key negotiation between the user, the base station and the target drone according to an embodiment of the present invention. The embodiment of the present invention provides a scalable drone Internet of Things authentication key negotiation method, including:

[0076] Step S1, initialize system parameters through the key management center, complete base station authorization and user registration, and perform mutual authentication between the base station and each drone;

[0077] Specifically, in step S1, the initialization of system parameters includes:

[0078] Step S11, defining system parameters and secure hash function;

[0079] Step S12, determining an additive cyclic group and its corresponding generator based on an elliptic curve over a finite field, randomly selecting a secret integer from the multiplication group of integers modulo q corresponding to the large prime order q of the generator, and determining a secret public key corresponding to the secret integer;

[0080] Step S13, storing the secret integer and publishing each system parameter.

[0081] In a specific embodiment, let p be a large prime number, and E be a finite field F defined in p Elliptic curve on the p , the points on E form an additive cyclic group G, whose generator P has a large prime order q, and two secure hash functions are defined and H:{0,1} * →{0,1} l , where l is the bit length of the function output, KMC also defines a medium integer ω, where 2 4 ≤ω≤2 8 , used to determine To ensure that the fuzzy verifier has the ability to resist password guessing attacks after the user's device is lost, KMC randomly selects a secret integer from the integer modulo q multiplication group And calculate its corresponding secret public key PK = msk·P, KMC secretly stores msk and publishes {E,p,q,P,PK,h,H,ω}.

[0082] The present invention utilizes the homomorphic properties of elliptic curve encryption to ensure privacy protection during information transmission. By defining a secure hash function, it can be used to verify the integrity of a message to ensure that the message has not been tampered with during transmission. A secret integer is randomly selected from an integer modulo q multiplication group, and the unpredictability of random numbers is utilized. The randomly generated secret integer is difficult to be guessed by an attacker, further enhancing the confidentiality of the system.

[0083] Specifically, in step S1, the base station authorization includes:

[0084] The key management center assigns a corresponding base station identity to each base station, generates a base station private key and a base station public key corresponding to each base station identity, initializes a permissioned blockchain, defines a calling function, and registers the base station as a node in the permissioned blockchain.

[0085] In a specific embodiment, the KMC assigns a unique identity to each base station. And generate the corresponding base station private key and the corresponding base station public key KMC also loads the group key s into all base stations and initializes a permissioned blockchain to store information of all legal entities and registers base stations as nodes in the blockchain. The blockchain records all identity changes and tracks the entire authentication process in the authentication information ledger. The base station defines calling functions authUAV, calling functions updInfo, and calling functions queryInfo. Calling function authUAV stores new authentication information in the ledger. When the drone or user updates its pseudonym, or KMC modifies membership, calling function updInfo updates the ledger to keep it up to date. Other entities can use the calling function queryInfo to query the blockchain node to obtain the latest member list.

[0086] The present invention manages user communications through a base station and assists data users in establishing connections with drones, thereby ensuring the communication quality and content security between users and drones, simplifying user operation procedures, and improving user experience.

[0087] See also Figure 2 As shown, it is a flowchart of the interaction between the user and the KMC during the user registration process; specifically, in the step S1, the user registration includes:

[0088] Step S14: the user selects a user password and randomly selects a random number from the integer modulo q multiplication group as a first random number, generates a corresponding user device identity and a verification password hash value, and sends the user device identity and the verification password hash value to the key management center;

[0089] Step S15, the key management center randomly selects a random number from the integer modulo q multiplication group as a security parameter, and determines a shared secret message and a hidden secret message based on the security parameter and the user equipment identity;

[0090] Step S16: The user activates the device based on the first random number and the user password, and randomly selects a random number from the integer modulo q multiplication group as the second random number to generate a corresponding verification device hash value.

[0091] In a specific embodiment, user U i Randomly select a random number from the multiplicative group of integers modulo q as the first random number and generate a unique user device identity User selects user password Calculate the hash value of the password and the random number cascade verification password The salted hashing technology is used to ensure that the KMC cannot obtain the plain text of the password and cannot directly guess the user password. Submit to KMC;

[0092] After receiving the message, KMC randomly generates a security parameter calculate as shared secret information and in XOR Get hidden secret message after hiding KMC will Stored in its database, and B i stored on the user’s access device;

[0093] After receiving the access device, the user enters the first random number r i and user password Activate device, user U i Randomly select a random number from the multiplication group of integers modulo q as the second random number And calculate the corresponding login password hash value XOR EPW' corresponding to the second random number i Get hidden secret message after hiding And determine the verification device hash value Used to verify the correctness of the password when the user logs in. Among them, ω defines the ability of the fuzzy verifier to detect device corruption, which can promptly detect device loss and damage to prevent offline password guessing attacks. If an illegal user obtains the user's device, by entering and Guess the user password. Since the device takes the modulus of ω for the calculation result during verification, at least |PW| / ω passwords will pass offline verification (|PW| is the size of the password space). Interactive password guessing is required, which will be detected by the BS. Finally, {r' i ,B i ,D i}, by updating the first random number r i is the second random number r' i , so that the server receives EP W' involved in the calculation of the device i Even if an attacker intercepts the registration process At the same time, obtain the parameter r' stored in the device i , and password guessing attacks are also not possible, where mod is a modulo operation.

[0094] The present invention lays the foundation for subsequent two-factor authentication by combining the user password and the user device identity, increasing the difficulty for attackers to crack identity authentication. By generating and sending the verification password hash value instead of directly sending the user password, the anti-collision property of the hash function ensures that different passwords are unlikely to generate the same hash value, further enhancing the accuracy and security of password verification.

[0095] Specifically, in step S1, the mutual authentication between the base station and each drone includes:

[0096] Step S17, the key management center randomly selects a number of random numbers from the integer modulo q multiplication group as the drone identity corresponding to each drone, determines the corresponding drone characteristics according to each drone identity, generates the corresponding pseudo drone identity, challenge and synchronization challenge, sends the drone identity, pseudo drone identity, challenge and synchronization challenge to the corresponding drone, and stores the drone identity and drone characteristics corresponding to each drone in the local database of the key management center;

[0097] Step S18, each drone determines a challenge response corresponding to each challenge and a synchronous challenge response corresponding to each synchronous challenge based on a physical non-cloning function, and sends the drone identity, challenge response and synchronous challenge response corresponding to each drone to a key management center;

[0098] Step S19, the key management center determines the challenge key, challenge reconstruction parameter, synchronous challenge key and synchronous challenge reconstruction parameter corresponding to each challenge response and synchronous challenge response based on the fuzzy extractor, and returns them to the corresponding drone and base station.

[0099] In a specific embodiment, KMC is Randomly generate mutually prime drone identities And calculate the comprehensive value of the drone , the first intermediate value First median value And the drone features S j =x j y j , KMC will Stored in a local database, it is used to solve the Chinese remainder theorem during subsequent key aggregation;

[0100] KMC on drone identity Generate a fake drone identity At the same time, a challenge C is generated j and a set of simultaneous challenges KMC sends Send to

[0101] Leveraging its unique embedded physical capabilities Extracting the Physical Unclonable Function (PUF) output And through the secure channel Sent to KMC, where R j For challenge response, To synchronize the challenge response;

[0102] KMC calculation and KMC then sends Return to the corresponding drone, and finally, KMC will Uploaded to the blockchain ledger and downloaded to the base station for subsequent communication with the drone; where FEGen(R): Given an input bit string R, it outputs a challenge key K FE and a reconstruction parameter RP, FERec(R', RP): Given a bit string R' similar to R and a reconstruction parameter RP as input, output the same key K FE , for The corresponding challenge key, for The corresponding challenge reconstruction parameters, for The corresponding synchronization challenge key, for Corresponding synchronization challenge reconstruction parameters, the physical uncloning function PUF can be represented by a challenge-response pair, R=PUF(C), where a given challenge C produces a unique response R.

[0103] The present invention can protect the physical security of drones and prevent attackers from capturing drones and tampering with them by means of interaction between the key management center and drones and the introduction of physical unclonable functions and fuzzy extractors in the authentication process. By generating pseudo-drone identities, challenges, and synchronization challenges corresponding to each drone, the problem of asynchrony between base stations and drones can be solved.

[0104] Step S2, in response to the user successfully logging in and sending a request message for establishing a connection request with several target drones in the target drone list, determining a first encrypted request message based on the temporary session key, and sending the first encrypted request message to a key base station; the key base station is a base station closest to the user;

[0105] See also Figure 3 As shown, it is a flowchart of the interaction between the key management center and the drone in an embodiment of the present invention; specifically, in the step S2, it includes:

[0106] Step S21, the user inputs the user device identity and the user password to the device to log in, determines the login password hash value and the login device hash value, and determines whether the user input matches based on the comparison result of the login device hash value and the verification device hash value. If they match, the user logs in successfully;

[0107] Step S22, the user randomly selects a random number from the integer modulo q multiplication group as a third random number, and determines a temporary private key and a temporary public key based on the shared secret information and the third random number;

[0108] Step S23, determining a temporary session key based on the temporary private key and the base station public key, encrypting the user pseudonym, the target drone identity, and the authentication hash based on the temporary session key to obtain a first encryption formula, and determining a first message hash digest based on the user pseudonym, the target drone identity, the authentication hash, and the first current timestamp;

[0109] Step S24: determine a first encryption request message based on the temporary public key, the first encryption formula, the first current timestamp and the first message hash digest, and send the first encryption request message to the key base station.

[0110] In a specific embodiment, user U i enter and Go to the device and calculate the login password hash value and login device hash value The user then verifies D' i Is it equal to D i , if it matches, access is allowed, otherwise login is denied;

[0111] U i Randomly select a third random number and first the current timestamp calculate Recover the shared secret information A during the registration phase i , (A i + g) as a temporary private key, and calculate the temporary public key X = (A i +g)·P, and then use the DH protocol to calculate the temporary session key Then, a pseudonym is determined to hide the user's true identity. Authentication Hash The pseudonym, target drone identity and authentication hash are encrypted using the temporary session key K to obtain the first encryption formula Then calculate the first message hash digest To protect the integrity of the message, finally, U i Sending a first encryption request message via an open channel To the key base station BS, Enc() is a symmetric encryption algorithm, Dec() is a symmetric decryption algorithm, ElEnc() is an asymmetric encryption algorithm, and ElDec() is an asymmetric decryption algorithm.

[0112] The present invention determines a temporary session key based on a temporary private key and a base station public key, utilizes the characteristics of asymmetric encryption to negotiate a symmetric temporary session key, does not need to rely on a pre-shared key, can improve the security and flexibility of communication, and encrypts the user pseudonym, the target drone identity and the authentication hash to obtain the first encryption formula, which can ensure the confidentiality of these sensitive information during transmission.

[0113] Step S3, the key base station decrypts the first encrypted request message based on the temporary session key and verifies the user identity. If the identity verification is successful, the key base station sends a connection request containing several target drones to the base stations corresponding to the drones.

[0114] Specifically, the step S3 includes:

[0115] Step S31, after receiving the first encryption request message, the key base station determines whether the first current timestamp meets a first determination condition, and if so, determines a temporary session key based on the temporary public key and the base station private key;

[0116] Step S32, decrypting the encrypted user pseudonym, target drone identity and authentication hash based on the temporary session key, and verifying the user identity. If the identity verification is successful, the key base station sends a connection request containing several target drones to the permission blockchain, and the permission blockchain sends the connection request to the base station corresponding to each drone;

[0117] The verification of the user identity includes verifying the first message hash digest and verifying the authentication hash.

[0118] In a specific embodiment, after receiving M1, the BS checks whether the first current timestamp satisfies the first determination condition |ts1-ts c |<Δt, then calculate the temporary session key The first encrypted CAK is decrypted using the temporary session key K to obtain And verify whether η is equal to like and η are invalid, BS terminates the process, and then calculates the real identity of the user The blockchain ledger formed in the authorization is retrieved, if In the ledger, BS retrieves the corresponding a i And calculate BS then verifies whether AK matches If the verification is successful, Send a transaction request authUAV containing a list of drones to the blockchain network to notify the BS responsible for the UAV, where: is the current timestamp, is the base station private key, is the base station public key, list is the target drone list, and Δt is the preset time interval, which can be set by the actual implementer according to the actual situation.

[0119] The present invention can avoid replay attacks and improve system security and communication integrity by determining whether the first current timestamp meets the first determination condition. The key base station determines the temporary session key based on the same principle as the sender (temporary public key and base station private key), ensuring that the same key is used for communication with the sender to prevent data from being tampered with or stolen.

[0120] Step S4, each base station searches whether there is any target drone in its corresponding airspace, and if so, determines a second encrypted request message based on the drone identity corresponding to the target drone, and sends the second encrypted request message to the target drone;

[0121] Specifically, in step S4, it includes:

[0122] Step S41, after receiving the connection request, each base station searches whether there is each target drone in its corresponding airspace. If yes, it determines it as the target base station and retrieves the corresponding drone identity from the local database, and determines its corresponding pseudo drone identity, challenge and challenge key;

[0123] Step S42, the target base station generates a second current timestamp and randomly selects a random number from the integer modulo q multiplication group as a fourth random number, and hides the user identity and the fourth random number based on the challenge key to obtain a hidden user identity and a hidden fourth random number;

[0124] Step S43, determining a second message hash digest based on the temporary public key, the hidden fourth random number, the challenge, the user identity, the fourth random number, and the second current timestamp, and determining a second encryption request message;

[0125] Step S44: The target base station sends the second encryption request message and the temporary public key to the corresponding target drone.

[0126] In a specific embodiment, after receiving authUAV, each BS checks whether there is any target UAV in the list in its airspace. If there is, it is identified as the target base station and retrieved from the database Corresponding PUF Challenge and Challenge Key Pair BS generates the second current timestamp And the fourth random number And use the challenge key Determine the user's true identity and hide the fourth random number Calculate the second message hash digest To protect the integrity of the message, the target base station will eventually send the second encrypted request message The temporary public key X is sent to the target drone in its airspace, where it is passed to the drone to encrypt the random number t generated subsequently. j , to provide confidentiality of the session key.

[0127] The present invention determines the pseudo drone identity for the target drone through the base station, provides a layer of protection for the real identity of the drone, determines the challenge and challenge key, introduces a challenge-response authentication mechanism, increases the complexity and reliability of authentication, and improves the system's ability to resist illegal drone access. The user identity is hidden based on the challenge key, so that the user identity is effectively protected during the transmission process.

[0128] Step S5, each of the target drones determines its corresponding secret message based on the second encryption request message, and encrypts the secret message and sends it to the key base station;

[0129] Specifically, the step S5 includes:

[0130] Step S51, after receiving the second encryption request message, each of the target drones determines whether the second current timestamp satisfies a second determination condition, and if so, reconstructs a challenge key based on a corresponding challenge reconstruction parameter;

[0131] Step S52, each of the target drones recovers the user identity and the hidden fourth random number based on the challenge key, and verifies whether the second message hash digest matches, and if so, determines a new challenge and a new response;

[0132] Step S53, each of the target drones randomly selects a random number from the integer modulo q multiplication group as a fifth random number and generates a random element, and encrypts the fifth random number based on the random element and the temporary public key to obtain a hidden fifth random number;

[0133] Step S54, each of the target drones determines a second encryption formula based on the corresponding pseudo drone identity, the new response, and the hidden fifth random number, and determines a third message hash digest based on the second encryption formula, the pseudo drone identity, the new response, the hidden fifth random number, and the third current timestamp, and determines a secret message, and sends the secret message to the corresponding target base station;

[0134] Step S55: Each of the target base stations sends the secret message to the key base station.

[0135] In a specific embodiment, the target drone Receive a second encryption request message from the target base station After that, first based on the second judgment condition Second current timestamp of verification message The validity of And reconstruct the challenge key based on the corresponding challenge response and challenge reconstruction parameters Then, the target drone Restore the user's real identity and the fourth random number Verify θ j Is it equal to If there is no match, the target drone Discard the message, otherwise, update the PUF challenge response pair and calculate a new challenge and new response , target drone A random number is randomly selected from the integer modulo q multiplication group as the fifth random number And generate a random element Encrypt t using the asymmetric encryption algorithm EC-1Gamal with the temporary public key X j ,Right now To prevent semi-honest base stations, the drone will use the temporary secret (fifth random number) t j Before sending to the Curiosity Base Station, it is encrypted using EC-ElGamal under the user-generated temporary public key X. The additive homomorphic property allows CRT aggregation to be performed on the encrypted data without decryption, which ensures that the drone can share t with the Curiosity Base Station. j Calculate while keeping t j Privacy, Select the third current timestamp Use the challenge key shared with the base station Encrypt the pseudonym, the new response and the hidden fifth random number to obtain the second encryption formula And calculate the third message hash digest To protect the integrity of the message, ultimately, each target drone Secret message Sent to key base stations.

[0136] The present invention ensures the timeliness of the received message by determining whether the second current timestamp meets the second determination condition, can avoid replay attacks, and improve system security and communication integrity. Reconstructing the challenge key based on the challenge reconstruction parameter, thereby restoring the user identity and hiding the fourth random number, and verifying whether the second message hash digest matches, can effectively prevent data leakage and illegal access, and realize a more powerful two-way authentication mechanism, which not only verifies the legitimacy of the user, but also proves its own legitimacy to the user. By determining new challenges and new responses, it increases the difficulty for attackers to crack the authentication process, making the authentication process more secure and reliable, and adapting to the ever-changing security threat environment.

[0137] Step S6, the key base station determines a target session message and a target secret message based on the Chinese remainder theorem and the secret message, and sends the target session message to each target drone, and sends the target secret message to the user;

[0138] Specifically, step S6 includes:

[0139] Step S61, after receiving the secret message corresponding to each target drone, the key base station determines whether the third current timestamp satisfies the third determination condition, and if so, decrypts the second encryption formula based on the challenge key, and verifies whether the third message hash digest matches;

[0140] Step S62, if there is a match, the key base station updates a new challenge based on the fourth random number and the challenge key, updates the pseudo drone identity based on the pseudo drone identity and the challenge key, updates the challenge key and the reconstruction parameter based on the new response, and obtains a third encryption formula;

[0141] Step S63, the key base station processes the fifth random number corresponding to each of the target drones and the drone characteristics based on the Chinese remainder theorem to determine an aggregate random number;

[0142] Step S64, the key base station generates the fourth current timestamp and the fifth current timestamp, determines a session identifier based on the challenge key corresponding to each of the target drones and the fourth current timestamp, and hides the session identifier to obtain a hidden session identifier;

[0143] Step S65, the key base station determines a fourth message hash digest based on the third encryption formula, the hidden session identifier, the updated reconstruction parameter, and the fourth current timestamp, and determines a target session message, and sends the target session message to each drone;

[0144] Step S66, the key base station encrypts the aggregate random number based on the temporary session key to obtain an encrypted aggregate random number, and determines a fifth message hash digest based on the encrypted aggregate random number, the session identifier, the aggregate random number and the fifth current timestamp, and determines a target secret message;

[0145] Step S67: the key base station sends the target secret message to the user.

[0146] In one specific embodiment, when all target drones send a secret message After arrival, the key base station is based on the third judgment condition Verify the third current timestamp of each message The validity of the challenge key is then Decrypted And verify the third message hash digest α j Is it equal to If they match, the key base station is updated and And call updInfo to update the account book, and then the key base station will update and encrypt to obtain the third encryption formula BS fourth current timestamp and fifth current timestamp Determining Aggregate Random Numbers Using the Chinese Remainder Theorem calculate As the session identifier in the session key, and determine the hidden session identifier Fourth message hash digest BS sends the target session message Sent to all target drones, BS encrypts the aggregate random number using the temporary session key K to determine the encrypted aggregate random number and the fifth message hash digest And send the target secret message Send to user U i .

[0147] The present invention ensures the timeliness of the received message by determining whether the third current timestamp meets the third determination condition, can avoid replay attacks, and improve system security and communication integrity. By aggregating the fifth random number and drone features corresponding to each target drone during the session through the Chinese remainder theorem, it is possible to achieve effective integration of multiple drone-related data and reduce the amount of data processing. The session identifier is determined based on the challenge key corresponding to each target drone and the fourth current timestamp. The confidentiality of the challenge key and the timeliness of the timestamp jointly guarantee the security of the session identifier. The challenge key is only known to authorized drones and key base stations, and the timestamp ensures that the session identifier is time-effective and difficult to be predicted or replayed by attackers. Hiding the session identifier further increases its confidentiality. Even if an attacker intercepts the communication data, it is difficult to obtain the real session identifier, thereby protecting the security and privacy of the session key negotiation process.

[0148] In step S7, each of the target drones determines a target session key based on the target session message, and the user determines a target session key based on the target secret message.

[0149] Specifically, step S7 includes:

[0150] Step S71, after receiving the target session message, each of the target drones determines whether the fourth current timestamp satisfies a fourth determination condition, and if so, determines an updated reconstruction parameter based on the fourth random number, the challenge key, and the third encryption formula, and verifies whether the fourth message hash digest matches;

[0151] Step S72: If there is a match, each of the target drones determines the hidden session identifier and updates the pseudo drone identity, and stores the updated pseudo drone identity, new challenge, and reconstruction parameters;

[0152] Step S73: Each of the target drones determines a target session key based on the hidden session identifier and the fifth random number.

[0153] In a specific embodiment, the secret message sent by the key base station Upon arrival, the target drone Based on the fourth determination condition |ts4-ts c |<Δt verification If the timeliness is satisfied, the updated reconstruction parameters are calculated. And verify that the fourth message hash digest β is equal to If the verification is successful, the target drone Determine hidden session ID And update the pseudo drone identity of the target drone And update in memory In preparation for the next interaction with the base station, finally, the target drone Calculate the target session key

[0154] Specifically, in step S7, it also includes:

[0155] Step S74, after receiving the target secret message, the user determines whether the fifth current timestamp satisfies the fifth determination condition, and if so, decrypts the encrypted aggregate random number based on the temporary session key, and verifies whether the fifth message hash digest matches;

[0156] Step S75: If they match, asymmetric decryption processing is performed on the aggregate random number based on the temporary private key to obtain a decrypted aggregate random number;

[0157] Step S76, the user determines the user session key based on the hidden session identifier and the decrypted aggregate random number;

[0158] Step S77: determining a target session key based on the user session key and the drone identity corresponding to the target drone.

[0159] In a specific embodiment, when user U i Receive the target base station After sending the target secret message M5, based on the fifth judgment condition |ts5-ts c |<Δt verification The timeliness of the encrypted aggregate random number CSR is obtained based on the temporary session key K. And check the calculated hash value Is it equal to γ? Verify the integrity of the message. Finally, U i Calculate user session key and from The target session key is derived from

[0160] The present invention initializes system parameters through a key management center, completes base station authorization and user registration, and performs mutual authentication between the base station and each drone, which can improve the security of communication. The centralized management of the key management center can improve the scalability of the system and facilitate flexible adjustment. By encrypting the user's request message based on a temporary session key, the security of the negotiation can be improved, ensuring that the key and the content of the request message are not stolen during the transmission process. By using a key base station to verify the user's identity and sending the connection request to the base station corresponding to each drone, it is possible to effectively prevent illegal users from accessing the system. If a large number of users send connection requests to drones in different areas, the precise forwarding mechanism of the key base station can ensure that the request quickly and accurately reaches the base station where the target drone is located, accelerating the connection establishment process. Each base station retrieves whether there is any target drone in its corresponding airspace, which can improve the utilization rate of communication resources, determine the second encrypted request message based on the drone identity corresponding to the target drone, and send the second encrypted request message to the target drone, further improving the security of the session key negotiation process. Each target drone determines its corresponding secret message based on the second encrypted request message, and encrypts the secret message and sends it to the key base station, which can effectively resist the threat of tampering after the device is captured, and ensure the physical security of the device. The key base station determines the target session message and target secret message based on the Chinese remainder theorem and secret messages, which can achieve efficient aggregation of multi-UAV session keys and maintain lightweight computing and communication overhead in the face of rapidly growing connection requirements. Each target UAV determines the target session key based on the target session message, and the user determines the target session key based on the target secret message, which can further improve the confidentiality of the session key and ensure privacy-preserving session key negotiation even in the presence of curious relay base stations.

[0161] In a specific embodiment, a legitimate user can update the password locally without the assistance of the KMC, and the process is as follows:

[0162] UserU i Will and new password Input device; device computing And verify Is it equal to D i If the input information is incorrect, the program is terminated and the device calculates and And update the storage information.

[0163] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. A scalable UAV Internet of Things authentication key negotiation method, characterized in that: include: Step S1, initialize system parameters through the key management center, complete base station authorization and user registration, and perform mutual authentication between the base station and each drone; Step S2, in response to the user successfully logging in and sending a request message for establishing a connection request with several target drones in the target drone list, determining a first encrypted request message based on the temporary session key, and sending the first encrypted request message to a key base station, wherein the key base station is a base station closest to the user; Step S3, the key base station decrypts the first encrypted request message based on the temporary session key and verifies the user identity. If the identity verification is successful, the key base station sends a connection request containing several target drones to the base stations corresponding to the drones. Step S4, each base station searches whether there is any target drone in its corresponding airspace, and if so, determines a second encrypted request message based on the drone identity corresponding to the target drone, and sends the second encrypted request message to the target drone; Step S5, each of the target drones determines its corresponding secret message based on the second encryption request message, and encrypts the secret message and sends it to the key base station; Step S6, the key base station determines a target session message and a target secret message based on the Chinese remainder theorem and the secret message, and sends the target session message to each target drone, and sends the target secret message to the user; In step S7, each of the target drones determines a target session key based on the target session message, and the user determines a target session key based on the target secret message.

2. The scalable UAV Internet of Things authentication key negotiation method according to claim 1, characterized in that: In the step S1, the initialization of system parameters includes: Step S11, defining system parameters and secure hash function; Step S12, determining an additive cyclic group and its corresponding generator based on an elliptic curve over a finite field, randomly selecting a secret integer from the multiplication group of integers modulo q corresponding to the large prime order q of the generator, and determining a secret public key corresponding to the secret integer; Step S13, storing the secret integer and publishing each system parameter.

3. The scalable UAV Internet of Things authentication key negotiation method according to claim 2, characterized in that: In the step S1, the base station authorization includes: The key management center assigns a corresponding base station identity to each base station, generates a base station private key and a base station public key corresponding to each base station identity, initializes a permissioned blockchain, defines a calling function, and registers the base station as a node in the permissioned blockchain.

4. The scalable UAV Internet of Things authentication key negotiation method according to claim 3 is characterized in that: In step S1, the user registration includes: Step S14: the user selects a user password and randomly selects a random number from the integer modulo q multiplication group as a first random number, generates a corresponding user device identity and a verification password hash value, and sends the user device identity and the verification password hash value to the key management center; Step S15, the key management center randomly selects a random number from the integer modulo q multiplication group as a security parameter, and determines a shared secret message and a hidden secret message based on the security parameter and the user equipment identity; Step S16: The user activates the device based on the first random number and the user password, and randomly selects a random number from the integer modulo q multiplication group as the second random number to generate a corresponding verification device hash value.

5. The scalable UAV Internet of Things authentication key negotiation method according to claim 4, characterized in that: In step S1, the mutual authentication between the base station and each drone includes: Step S17, the key management center randomly selects a number of random numbers from the integer modulo q multiplication group as the drone identity corresponding to each drone, determines the corresponding drone characteristics according to each drone identity, generates the corresponding pseudo drone identity, challenge and synchronization challenge, sends the drone identity, pseudo drone identity, challenge and synchronization challenge to the corresponding drone, and stores the drone identity and drone characteristics corresponding to each drone in the local database of the key management center; Step S18, each drone determines a challenge response corresponding to each challenge and a synchronous challenge response corresponding to each synchronous challenge based on a physical non-cloning function, and sends the drone identity, challenge response and synchronous challenge response corresponding to each drone to a key management center; Step S19, the key management center determines the challenge key, challenge reconstruction parameter, synchronous challenge key and synchronous challenge reconstruction parameter corresponding to each challenge response and synchronous challenge response based on the fuzzy extractor, and returns them to the corresponding drone and base station.

6. The scalable UAV Internet of Things authentication key negotiation method according to claim 5, characterized in that: In the step S2, it includes: Step S21, the user inputs the user device identity and the user password to the device to log in, determines the login password hash value and the login device hash value, and determines whether the user input matches based on the comparison result of the login device hash value and the verification device hash value. If they match, the user logs in successfully; Step S22, the user randomly selects a random number from the integer modulo q multiplication group as a third random number, and determines a temporary private key and a temporary public key based on the shared secret information and the third random number; Step S23, determining a temporary session key based on the temporary private key and the base station public key, encrypting the user pseudonym, the target drone identity, and the authentication hash based on the temporary session key to obtain a first encryption formula, and determining a first message hash digest based on the user pseudonym, the target drone identity, the authentication hash, and the first current timestamp; Step S24: determine a first encryption request message based on the temporary public key, the first encryption formula, the first current timestamp and the first message hash digest, and send the first encryption request message to the key base station.

7. The scalable UAV Internet of Things authentication key negotiation method according to claim 6, characterized in that: In the step S3, it includes: Step S31, after receiving the first encryption request message, the key base station determines whether the first current timestamp meets a first determination condition, and if so, determines a temporary session key based on the temporary public key and the base station private key; Step S32, decrypting the encrypted user pseudonym, target drone identity and authentication hash based on the temporary session key, and verifying the user identity. If the identity verification is successful, the key base station sends a connection request containing several target drones to the permission blockchain, and the permission blockchain sends the connection request to the base station corresponding to each drone; The verification of the user identity includes verifying the first message hash digest and verifying the authentication hash.

8. The scalable UAV Internet of Things authentication key negotiation method according to claim 7, characterized in that: In the step S4, it includes: Step S41, after receiving the connection request, each base station searches whether there is each target drone in its corresponding airspace. If yes, it determines it as the target base station and retrieves the corresponding drone identity from the local database, and determines its corresponding pseudo drone identity, challenge and challenge key; Step S42, the target base station generates a second current timestamp and randomly selects a random number from the integer modulo q multiplication group as a fourth random number, and hides the user identity and the fourth random number based on the challenge key to obtain a hidden user identity and a hidden fourth random number; Step S43, determining a second message hash digest based on the temporary public key, the hidden fourth random number, the challenge, the user identity, the fourth random number, and the second current timestamp, and determining a second encryption request message; Step S44: The target base station sends the second encryption request message and the temporary public key to the corresponding target drone.

9. The scalable UAV Internet of Things authentication key negotiation method according to claim 8, characterized in that: In the step S5, it includes: Step S51, after receiving the second encryption request message, each of the target drones determines whether the second current timestamp satisfies a second determination condition, and if so, reconstructs a challenge key based on a corresponding challenge reconstruction parameter; Step S52, each of the target drones recovers the user identity and the hidden fourth random number based on the challenge key, and verifies whether the second message hash digest matches, and if so, determines a new challenge and a new response; Step S53, each of the target drones randomly selects a random number from the integer modulo q multiplication group as a fifth random number and generates a random element, and encrypts the fifth random number based on the random element and the temporary public key to obtain a hidden fifth random number; Step S54, each of the target drones determines a second encryption formula based on the corresponding pseudo drone identity, the new response, and the hidden fifth random number, and determines a third message hash digest based on the second encryption formula, the pseudo drone identity, the new response, the hidden fifth random number, and the third current timestamp, and determines a secret message, and sends the secret message to the corresponding target base station; Step S55: Each of the target base stations sends the secret message to the key base station.

10. The scalable UAV Internet of Things authentication key negotiation method according to claim 9, characterized in that: In the step S6, it includes: Step S61, after receiving the secret message corresponding to each target drone, the key base station determines whether the third current timestamp satisfies the third determination condition, and if so, decrypts the second encryption formula based on the challenge key, and verifies whether the third message hash digest matches; Step S62, if there is a match, the key base station updates a new challenge based on the fourth random number and the challenge key, updates the pseudo drone identity based on the pseudo drone identity and the challenge key, updates the challenge key and the reconstruction parameter based on the new response, and obtains a third encryption formula; Step S63, the key base station processes the fifth random number corresponding to each of the target drones and the drone characteristics based on the Chinese remainder theorem to determine an aggregate random number; Step S64, the key base station generates the fourth current timestamp and the fifth current timestamp, determines a session identifier based on the challenge key corresponding to each of the target drones and the fourth current timestamp, and hides the session identifier to obtain a hidden session identifier; Step S65, the key base station determines a fourth message hash digest based on the third encryption formula, the hidden session identifier, the updated reconstruction parameter, and the fourth current timestamp, and determines a target session message, and sends the target session message to each drone; Step S66, the key base station encrypts the aggregate random number based on the temporary session key to obtain an encrypted aggregate random number, and determines a fifth message hash digest based on the encrypted aggregate random number, the session identifier, the aggregate random number and the fifth current timestamp, and determines a target secret message; Step S67: the key base station sends the target secret message to the user.

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