229 results about "Key generation center" patented technology

The invention relates to a cloud data auditing method based on a block chain, and the method comprises the steps: S1, a key generation center generates system parameters and generates a user part private key based on a user identity, a user generates an authorization private key based on the part private key and sends an authorization request to a proxy server, and the proxy server generates an encryption key pair after verifying the request; s2, a user locally performs block blinding on original data blocks, a proxy server signs the data blocks and generates a Merkel Hash tree based on a bucket structure, and a cloud service provider performs integrity verification on received user files, stores data and uploads Merkel Hash tree root values to a block chain; s3, the third-party auditing mechanism generates a challenge request and sends the challenge request to the cloud service provider after receiving the auditing request of the user, the cloud service provider generates a challenge response according to parameters in a challenge set, and the third-party auditing mechanism judges whether data stored in the cloud are complete or not based on bilinear mapping; and returning the audit result to the user and generating a transaction record on the block chain.

The invention discloses a multi-chain collaborative center node switching method for ensuring authentication efficiency and data reliability, which is applied to a system comprising an identity chain, an authentication chain, an edge computing center, a key generation center, a plurality of unmanned aerial vehicle clusters and at least two aerial directors, and is characterized in that the identity chain is used for identity management of all the unmanned aerial vehicle clusters; the authentication chain is jointly maintained by all the unmanned aerial vehicle clusters and all the air directors. According to the multi-chain collaborative central node switching method for ensuring the authentication efficiency and the data reliability provided by the invention, the secure communication between the clusters can be quickly established in the authentication process of the unmanned aerial vehicle clusters, and the switching of the central nodes can be quickly carried out when the central nodes are threatened and attacked in a multi-chain manner; the new central node continues to execute the flight task, and the forward and backward security is ensured in the switching process, so that the problems of low authentication efficiency of the unmanned aerial vehicle cluster, strong dependency of the central node and insufficient security in the switching process of the central node are solved.

The invention discloses an unmanned aerial vehicle cluster-oriented lightweight dynamic asymmetric group key negotiation method and system, a key generation center generates system public and private keys and public parameters, unmanned aerial vehicles and a ground station register and verify partial public and private keys and complete public and private keys, and the ground station precomputes an initialized table to assist subsequent operation. The unmanned aerial vehicles generate signature messages respectively and send the signature messages to ground station nodes for identity verification, the ground stations negotiate and publish asymmetric group encryption keys to the block chain, and the unmanned aerial vehicles generate respective decryption keys; when a new unmanned aerial vehicle applies for joining, a signature message is sent to a ground station node, the ground station updates and publishes the asymmetric group encryption key, and the unmanned aerial vehicles update respective decryption keys; when the unmanned aerial vehicles apply for leaving, a leaving message is sent to the ground station node, the ground station updates and publishes the asymmetric group encryption key, and the unmanned aerial vehicles update respective decryption keys; the pairing-free certificateless asymmetric group key negotiation is realized, and the calculation and communication efficiency is improved.

The invention provides an identity authentication method and system for resisting an identity forgery attack, which are used for guaranteeing the safety of cross-domain communication. The method comprises the following steps: firstly, initializing a system, and generating a key pair for an entity based on an elliptic curve; when the user registers in the domain, the authentication center generates a key pair, encryption parameters and an identity certificate and stores the key pair, the encryption parameters and the identity certificate in the slave chain. A key generation center (KGC) pre-generates a factor including a private key and pre-loads the factor to a roadside unit (RSU). When a user initiates a pseudonym generation request, the RSU verifies the request and forwards the request to a nearby base station; and the base station predicts a resource use state by using an AI model, and dynamically assigns a service base station to calculate pseudonym generation parameters in real time. A user generates own pseudonym, verification parameters and a key pair after obtaining the parameters, and generates a unique signature by using the pseudonym key to encrypt a message and send the encrypted message. After the receiver verifies the validity of the message, a verification request is forwarded to the base station through the RSU, the service base station is dynamically assigned to verify the legality of the pseudonym based on the AI strategy, and a user identity certificate is inquired and verified through carrying address information cross-chain (slave chain / main chain cooperation). According to the method, malicious vehicles with fake kana can be effectively identified, dynamic scheduling of resources is realized by using AI, and the low-delay requirement is met.

According to the anti-frequency analysis searchable encryption method and system, a certificateless encryption system is introduced, for a scene with limited computing resources, the scheme is ensured to be safe and suitable for the scene with the limited computing resources, meanwhile, a trap door algorithm is designed based on a probability trap door generation algorithm, and the security of the scheme is improved. The method improves the resistance of a system to frequency analysis attacks, solves the problem of secret key trusteeship due to the fact that identity information and secret key distribution are concentrated in a private key generation center in a traditional encryption scheme, and improves the encryption efficiency. The technical problem that malicious users are easy to obtain the privacy information of the target keyword by performing frequency analysis on trap doors and initiating keyword guessing attacks is solved.

The invention relates to a data security technology, and discloses a medical data trusted processing method based on an intelligent contract, which comprises the following steps: a key generation center generates system public parameters and a system master key; the data purchaser initiates a medical data transaction application to the block chain platform according to the transaction number, the medical data processing keyword and the data purchaser IP address, and deploys an intelligent contract in the block chain platform; the data purchaser and the data manager serve as two transaction parties to generate data demand features according to the smart contract; the data manager encrypts the medical data according to the data demand features to obtain encrypted medical data; the data manager performs zero-knowledge verification, and the proxy re-encryption module converts the encrypted medical data into an intermediary ciphertext and sends the intermediary ciphertext to the data purchaser; and the data purchaser decrypts the medium ciphertext to obtain the medical data. The invention further provides a system of the medical data credible processing method based on the smart contract, data privacy can be protected, and the maintenance cost of the medical data can be reduced.

According to the multi-user hierarchical data cloud storage sharing method and system based on secret sharing provided by the invention, storage protection is provided for an encryption key by using a secret sharing mechanism, so that the security of the key can be effectively ensured; different shared user groups and shared data grading contents are set according to different key shares, and attribute encryption can be equivalently realized; the access control server performs processing such as interpolation, slicing and transposition on an external storage key share, so that proxy re-encryption can be efficiently and equivalently realized; the secret key share is simultaneously used for realizing the processes of shared user group setting, shared data grading encryption, shared user and access control server bidirectional authentication, proxy re-encryption and the like, so that password resources are fully utilized. In addition, a key generation center is not needed, the interaction process of roles in the system is reduced, and the working process is simplified; and only simple Hash operation is needed, so that the generation of password resources is quicker, and the calculation is simpler and more efficient.

The invention discloses a balanced SM9 digital signature multi-party adapter signature generation method and system, a secret key generation center initializes system parameters according to security parameters in a symmetric environment, generates participant private key fragments by using a secret sharing technology, and generates a public and private key pair for a multiplication-to-addition ideal function for each participant; the participant requesting the pre-signature generates a difficult relation instance and a zero-knowledge proof and broadcasts the difficult relation instance and the zero-knowledge proof, the other participants calculate the pre-signature after verification, the legality of the pre-signature is verified by verifying a temporary variable, and a complete signature is calculated under the condition that the pre-signature is legal; adapter signature evidences are extracted according to the pre-signatures, the complete signatures and the difficult relation instances, evidence extraction is completed under the condition that instances generated by the adapter signature evidences are consistent with the difficult relation instances, and the national secret SM9 pre-signatures with the adapter function can be cooperatively generated under the condition that multiple participants jointly participate in operation in the symmetric environment; and the signature of the adapter is completed.

The invention discloses an identity privacy protection system and method oriented to power data security sharing, which combine single-factor combination authentication and identity traceability and utilize the transparency and tamper resistance of a block chain. Comprising an electric power key generation center, an electric power cloud service provider, an electric power data owner, an electric power data user and a block chain, user identity privacy is ensured, safe identity verification is supported, identity traceability is achieved under necessary conditions, and meanwhile safe distribution of keys is achieved. In addition, services and resources are isolated by using groups, so that the flexibility and the expandability of the services and the resources are enhanced. Security analysis and experimental evaluation prove that the method can effectively resist selected plaintext attacks, and meanwhile, high efficiency and practicability are kept.

The invention provides an SM9-based identity-based searchable public key encryption method and an SM9-based identity-based searchable public key encryption system. The system comprises a key generation center, a cloud storage server and a file sending and receiving party. A secret key generation center generates system public and private keys by using an SM9 algorithm, and generates a private key for a user in combination with identity information of the user. The file sender uses the user identity of the receiver and the file keyword to generate a keyword index and uploads the keyword index to the cloud server; when a receiver retrieves the file, the auxiliary parameters in the index are firstly obtained from the cloud server, then a keyword trap door is generated through a private key of the receiver, and the keyword trap door is uploaded to the cloud server; and the server compares the index with the trap door through a matching algorithm, and returns a corresponding ciphertext file to a receiver for decryption if matching succeeds. The secret key generation method is consistent with an SM9 algorithm, the application field of SM9 is expanded, and the safe and efficient searchable public key encryption method which does not need certificate management and can effectively resist internal keyword guessing attacks is achieved.

The invention belongs to the field of secure communication in the Internet of Vehicles, and particularly relates to a lightweight certificateless signcryption method capable of proving security in the Internet of Vehicles, which comprises the following steps: constructing an Internet of Vehicles system consisting of a key generation center KGC, a roadside unit, a vehicle and a block chain, and initializing system parameters; the vehicle-mounted unit in the vehicle and the roadside unit outside the vehicle respectively register in the key generation center, and system parameters and pseudonyms are returned after KGC verification is passed; the KGC generates a part of keys for the pseudonym and returns the keys to the vehicle, and the vehicle calculates and generates a key and a public key according to the returned part of keys and the pseudonym, and uploads the public key and the pseudonym to the block chain; the vehicle signcrypts the message according to the key, obtains the public key of the receiver from the block chain according to the pseudonym of the opposite side, and then sends the signcryption message to the receiver; and the target vehicle or the roadside unit receives the message and performs message de-signcryption, and uploads a transaction record to the block chain for storage. According to the invention, while anonymous and secure communication of each entity in the Internet of Vehicles system is ensured, the communication efficiency is improved by reducing the vehicle calculation pressure and the communication overhead.

The invention discloses a cloud data integrity auditing method, system, device, medium and product based on certificateless signature, and relates to the technical field of network security, the method comprises the following steps: a key generation center obtains a data owner anonymous identity label based on a system master secret key and a data owner real identity label, and sends the data owner anonymous identity label to a server; obtaining a part of private keys of the data owner based on the anonymous identity identifier; the data owner verifies part of the private keys according to the anonymous identity identification, secretly selects the random number as the other part of the private keys if the verification is passed, and obtains a public key according to the other part of the private keys; the data owner obtains the label of each data block based on the two parts of private keys; the third-party auditor initiates an integrity challenge to the cloud service provider; the cloud service provider calculates audit evidence; and the third-party auditor verifies whether the to-be-audited file stored in the cloud is complete or not. According to the application, the TPA can be prevented from exploring privacy, certificate management is simplified, efficient and rapid identity authentication is realized, and real information of a user is hidden.

The invention discloses an unmanned aerial vehicle mobile edge computing security authentication method and system based on identity-based encryption and a physical unclonable function, and belongs to the field of mobile edge computing and unmanned aerial vehicle communication security. A physical response is generated in combination with PUF hardware of the unmanned aerial vehicle node, the physical response and the ID are bound as a credible voucher, and meanwhile, a derived private key for IBE is generated for the unmanned aerial vehicle node based on the ID; after the unmanned aerial vehicle is networked, the KGC periodically initiates challenge response verification, the unmanned aerial vehicle generates a current response by using PUF hardware and returns the current response, the KGC performs comparison, and if an abnormality occurs, the KGC broadcasts to a full text to isolate an abnormal node; iBE is directly carried out on the basis of the ID of the receiver in communication between the unmanned aerial vehicles, and certificate exchange overhead is avoided. According to the method, lightweight identity authentication, physical attack resistance and efficient key management under dynamic topology are realized, and the method is suitable for unmanned aerial vehicle edge computing scenes with limited resources.

The invention discloses a data controlled sharing method and system based on attribute-based encryption, and the system is characterized in that a key generation center generates a system public key PK, a main private key MK and a user private key SK, a server gateway configures an access strategy, carries out the encryption processing of a data plaintext and the access strategy, generates a ciphertext, and uploads the ciphertext to a storage device for storage. Wherein the access strategy is converted into a mode that an LSSS matrix is embedded into a ciphertext; the one or more data controlled sharing gateways verify whether the attribute set of the data decryption party meets the access strategy according to the ciphertext and the user private key; if yes, the data plaintext is recovered and obtained by calculating the reconstruction coefficient of the LSSS matrix. According to the invention, the algorithm is simplified, and the system operation efficiency and stability are improved; the system does not need to adopt block chain storage, so that the system architecture design is simplified, the deployment is convenient, the cost is low, and the data security is high.

The invention discloses a quantum security aggregation signature method suitable for an embedded system, and the method comprises the steps: initializing system parameters through a trusted key generation center, and generating a pair of public and private keys for each signature user; the signature user signs the message by adopting a signature algorithm and a private key of the signature user, and sends a generated signature result, the message and a digital certificate of the message to the aggregation server; the aggregation server executes an aggregation algorithm according to the received information, multiple signatures are combined into an aggregation signature, and the aggregation signature and related information are sent to a verification server; and the verification server verifies the aggregation signature by using system parameters provided by the trusted key generation center and a public key of the aggregation server so as to ensure the integrity and correctness of the signature, thereby verifying the source of the message and the availability of the message. The method is suitable for various embedded systems with numerous edge nodes and limited computing resources, such as application scenes of unmanned aerial vehicle cluster safety communication, medical wireless sensor safety communication, intelligent network connection automobile and even satellite safety communication and the like.

The invention relates to a data transaction technology, and discloses a privacy enhanced trusted data transaction method based on an alliance chain, which comprises the following steps: a key generation center generates a system parameter list; the data owner calculates a shared key according to the system parameter list, calculates an encrypted ciphertext and uploads the encrypted ciphertext to a decentralized storage network; the decentralized storage network receives the encrypted ciphertext, generates a unique content identifier and divides the encrypted ciphertext into a plurality of ciphertext fragments; calculating a root node hash value, and recording the root node hash value and the unique content identifier into an alliance chain; and the data purchaser encrypts the data demand and issues the data demand through the alliance chain, and the alliance chain matches the transaction data according to the corresponding demand attribute in the data demand and performs decryption operation to obtain the required transaction data. The invention further provides a system of the privacy enhanced trusted data transaction method based on the alliance chain, the secure transaction of the data can be realized, and the controllability of the data in the transaction process is improved.

The invention discloses an Internet of Vehicles heterogeneous signcryption communication system and method based on a double-layer block chain, relates to the technical field of Internet of Vehicles, and solves the technical problems that the Internet of Vehicles technology is insufficient in expansibility and poor in compatibility, safety and efficiency are difficult to consider, and use requirements are difficult to meet. The system comprises a private key generation center PKG, a secret key generation center KGC, an on-board unit OBU, a roadside unit RSU and a double-layer block chain device. The private key generation center PKG is used for generating and distributing a public key and private key pair of the identity signcryption IBC; the key generation center KGC is used for key updating and management of the certificateless signcryption CLC; the OBU is used for performing communication between the vehicle and other vehicles or the road side unit; the roadside unit RSU is used for communication support and data forwarding; and the double-layer block chain equipment is used for carrying out data storage and security verification in the communication system. According to the invention, the calculation overhead and communication cost of the system are obviously reduced, and safe, efficient and extensible authentication and data transmission in a high-dynamic and large-scale V2X environment is realized.

The invention discloses an unmanned aerial vehicle cluster dynamic cross-domain key management method and system based on the Chinese remainder theorem (CRT), a key generation center generates system public and private keys and public parameters, and a ground station and an unmanned aerial vehicle perform hierarchical registration and verify respective keys; the unmanned aerial vehicles respectively generate signature messages and send the signature messages to a specified ground station for identity verification, and the ground station constructs a group key based on CRT and publishes the group key to the block chain; when a new unmanned aerial vehicle applies for joining, a signature message is sent to the ground station, and the ground station updates and publishes the group key; when the unmanned aerial vehicle applies for leaving, a leaving message is sent to the ground station, and the ground station updates and publishes the group key. According to the method, complex operations such as bilinear pairing operation and large integer modular exponentiation operation are avoided by optimizing the group key derivation process based on the CRT, and the calculation complexity is remarkably reduced. Meanwhile, efficient cross-domain authentication and batch verification are realized through Pedersen commitment and a zero-knowledge proof technology, and communication and calculation overhead is reduced.

The invention provides an equipment authentication method and device for a power terminal, electronic equipment and a storage medium, and the method comprises the steps: carrying out the local sensitive hash calculation of factory parameters of to-be-verified equipment, and obtaining a secret value; and signing the equipment access message based on the secret value, the equipment private key and a public key of an authentication server to obtain signature authentication information, and sending the signature authentication information to the authentication server, so that the authentication server receives the signature authentication information and sends the signature authentication information to the authentication server based on the equipment public key, a public key of a key generation center and a private key of the authentication server. And verifying the signature authentication information, and determining a verification result. Based on the pseudonym and the secret value generated by information fusion, the real identity of the equipment can be prevented from being directly exposed, and the security risk caused by identity information leakage is reduced. Verification is carried out based on the equipment public key, the public key of the key generation center and the private key of the authentication server, a key verification mechanism provides multi-level verification guarantee, and the reliability of a verification result is improved.

The invention discloses an identification-based lightweight hierarchical trust access authentication method and system, and mainly relates to the technical field of network security. Comprising the following steps: in an offline stage, an electric power registration center generates a private key root bound with an identity for a terminal through identity-based cryptography, a key generation center derives a lightweight work key voucher and pre-calculates verification points of all terminals, and a unified main multi-dimensional Bloom filter is constructed and distributed to a main station; in the online stage, a terminal updates a key and generates a signature only through hash operation, a master station reconstructs candidate verification points after receiving a message, and non-interactive verification is completed by locally querying a master multi-dimensional bloom filter. The method has the advantages that unification of strong identity credibility and extreme light weight of the terminal is achieved, the terminal side only needs efficient Hash operation, the server supports high-concurrency and low-delay authentication through the pre-calculation and Bloom filter technology, and the problem of safe access of massive distributed terminals in the electric power Internet of Things is effectively solved.

The invention relates to the technical field of information security, and particularly discloses a super SIM (Subscriber Identity Module) card key generation system and method supporting a SM9 cryptographic algorithm, and the system comprises terminal equipment, a super SIM card installed in the terminal equipment, an Internet of Things platform and a key generation center, the terminal equipment provided with the super SIM card forwards information through the Internet of Things platform or directly communicates with the key generation center, a framework in which the key generation center participates in key generation is provided for a national secret SM9 algorithm, and the super SIM card and the key generation center adopt a root key calculation identification code to perform bidirectional identity authentication. According to the super SIM card key generation system supporting the SM9 cryptographic algorithm, the security and integrity of communication in the key generation stage are ensured, namely, in the super SIM card key generation system supporting the SM9 cryptographic algorithm in the embodiment of the invention, the super SIM card can support the SM9 cryptographic algorithm, which is beneficial for using the SM9 cryptographic algorithm to perform information encryption in the Internet of Things, simplifying the key management process and reducing the cost and the system complexity.

The invention provides a cleanable certificateless signcryption method, a cleanable certificateless signcryption device, cleanable certificateless signcryption equipment and a cleanable certificateless signcryption system. Receiving a signcryption ciphertext which is sent by the data sending end and contains signature information and ciphertext information; verifying the signcryption ciphertext according to the public parameter and the key information; and after the verification is passed, re-randomizing signature information and ciphertext information in the signcryption ciphertext in an undecrypted state to obtain a purified signcryption ciphertext, and sending the purified signcryption ciphertext to a data receiving end to trigger the data receiving end to verify and decrypt the purified signcryption ciphertext to obtain plaintext information corresponding to the ciphertext information. According to the method and the device, the signcryption ciphertext can be re-random on the premise that the ciphertext is not unlocked, and meanwhile, the re-random signcryption ciphertext is ensured to still meet confidentiality and integrity and can be verified by a receiving end, so that leakage attack behaviors of a malicious data sender are effectively prevented.

The invention discloses a cloud-based Internet of Vehicles data sharing method, which comprises the following steps that: under a certificateless framework, a secret key generation center distributes part of private keys, and a user combines local secret key values into a complete private key; a data owner encrypts and uploads traffic data based on bilinear mapping, and then constructs a re-encryption key through polynomial interpolation, so that a cloud server can decrypt all receivers in an authorization set through one-time re-encryption, and meanwhile, the identities of the receivers are hidden. Timestamp embedding achieves temporary entrustment, and the cloud does not make contact with plaintexts and private keys in the whole process. According to the scheme, key escrow is eliminated, terminal communication calculation overhead is reduced, and anonymous, fine-grained and time-efficient data sharing requirements of the Internet of Vehicles are met.

The invention provides an anonymous method and system for a smart electric meter, and the method comprises the steps: building a key generation center, and enabling the smart electric meter and an aggregator to carry out the registration of the key generation center when the smart electric meter and the aggregator join a smart power grid for the first time; the intelligent electric meter encrypts an identity label and a timestamp of the intelligent electric meter by using an intelligent electric meter public key, generates an authentication request message according to the encrypted identity label and timestamp of the intelligent electric meter, and sends the authentication request message to the aggregator; the aggregator verifies the authentication request message after receiving the authentication request message, and generates an authentication response message and sends the authentication response message to the intelligent electric meter under the condition that the verification result is successful; and after receiving the authentication response message, the intelligent electric meter verifies the authentication response message, and under the condition that the verification result is successful, the two parties establish a shared session key to complete the authentication process. According to the method, the problems of low calculation efficiency, insufficient privacy protection, complex authentication process and the like in the prior art are effectively solved.

The invention discloses a privacy protection and traceable anonymous bidirectional authentication method for heterogeneous Internet of Vehicles, which comprises the following steps: generating public and private keys based on a key generation center, a private key generator and a trusted registration mechanism, and constructing a heterogeneous password system; the vehicle completes key registration by fusing the certificateless public key system, and the roadside unit completes key registration based on the identity public key system; the vehicle registers and uses the pseudonym to communicate with the roadside unit; and the vehicle and roadside unit bidirectional authentication verifies the legality of the opposite side through a hash function and a temporary value, and finally generates a session key. According to the invention, by providing traceable pseudonym and anonymous authentication communication for each vehicle, the privacy of the vehicle can be effectively protected, and an attacker can be prevented from tracking the identity information of the vehicle. Based on various security hypotheses, the method meets various security attributes including anonymity, unlinkability, perfect forward security, security of known temporary information specific to sessions and the like, and the security of data transmission of the Internet of Vehicles can be improved.

The invention discloses an image release privacy protection method based on attribute encryption, which solves the problems that in the prior art, access control expansibility is poor, an image processing mode damages visibility and a sensitive area is not self-defined, realizes safe image access control, ensures that only an authorized user can decrypt and recover an original image, and improves user experience. Meanwhile, the sensitive area is protected from unauthorized access; the method comprises the following steps: initializing an attribute-based encryption system through a key generation center, and distributing a public key and a user private key to realize fine-grained access control. And an image owner scrambles image color blocks by using DCT (Discrete Cosine Transform), and steganoscopes control parameters in the image to be published. And after the authorized visitor extracts the encryption parameter, the private key is used for decryption to obtain the original key, and the auxiliary information is combined to perform inverse operation on the image sensitive area to accurately recover the original image. In the whole process, flexible access control is achieved, and meanwhile protection and availability of image content are effectively balanced.

The invention discloses a model file distribution method and device, a storage medium and a processor. In the scheme, a key generation center generates key data of a model owner based on an identifier of the model owner, and generates key data of a model user based on an identifier of the model user; the model owner encrypts the original model file based on the encryption element and the main public key, generates a re-encryption key, and sends the encryption element, the re-encryption key and the encrypted model file to the key agent center; the key agent center generates a re-encryption ciphertext based on the encryption element and the re-encryption key, and sends the re-encryption ciphertext and the encrypted model file to a model user; and the model user decrypts the encrypted model file based on the key data of the model user, the re-encrypted ciphertext and the main public key to obtain an original model file. Compared with the problems of poor security and low encryption and decryption efficiency in the model file distribution process, the method has obvious advantages.

The application relates to the technical field of information security, in particular to a commercial cipher digital certificate generation method supporting quantum-resistant cipher, which comprises the following steps: a certificate authority generates a hybrid signature self-signed certificate with quantum-resistant cipher signature and traditional public key cipher signature; a user generates a hybrid signature certificate request file and sends the file to the certificate authority; the certificate authority generates a hybrid signature user signature certificate; a key generation center generates a user traditional public key cipher encryption key pair and a user quantum-resistant cipher encryption key pair; the certificate authority generates a hybrid signature user encryption certificate; the certificate authority generates a hybrid encryption public key, a private key encryption ciphertext and a hybrid ciphertext; and the user extracts the hybrid signature signature certificate, the encryption certificate, the quantum-resistant cipher encryption private key and the traditional public key cipher encryption private key, and verifies the signature certificate and the encryption certificate. The application can resist quantum attacks and is compatible with existing digital certificates.

The application relates to a cloud auditing method and system for anonymous data. The method comprises the following steps: a group administrator sets an initial group state, a key generation center (PKG) generates a master key, a partial key and public parameters; the group administrator allocates a unique identifier to each group user; the group administrator generates a first key pair and distributes the first key pair to the corresponding group user; the group user generates a file label, calculates a corresponding verifier for each block of the file, and a cloud server verifies the correctness of the file label and the verifier; a third-party auditor (TPA) generates an auditing challenge; the cloud server creates a corresponding proof; and the TPA verifies the correctness of the proof. The technical scheme provided by the application introduces a new anonymous strategy in the auditing model, an anonymous strategy based on group element equivalence class replacement realizes anonymity and traceability only with constant level consumption, and can simultaneously support the functions of anonymity, user revocation and traceability.

The present invention relates to a backward-secure certificateless authentication and key negotiation method, which belongs to the technical field of cryptography and solves the problem in the prior art that certificateless authentication and key negotiation schemes cannot achieve backward security for the communication parties. The method comprises the following steps: a key generation center outputs system parameters and secretly stores a master key based on input security parameters, wherein the system parameters include a hash function for generating a random state value of a fixed bit length, and the system parameters are system parameters of a communication system composed of several user terminals; the key generation center and each user terminal generate a public-private key pair for each user terminal based on the system parameters, the user identity of the user terminal, and the master key; and user terminals to be in a conversation perform authentication based on their respective public-private key pairs, system parameters, and identity information of both parties, generate a session key between the user terminals, and update the common state value between the user terminals based on the session key and the common state value between the user terminals.