On-lattice identity-based cloud storage integrity detection method and system

Abstract

The invention provides an identity-based cloud storage integrity detection method and system on lattices, and the method comprises the steps: generating system parameters according to a key generation center PKG through a lattice password technology, generating private keys of a user and a cloud server CS through the PKG, and completing the key distribution; the User divides the data file into smaller data blocks, signs the data blocks and sends the data blocks to the CS for storage, and data uploading is completed. As the data blocks are small, the calculation efficiency of the new method is improved. According to the auditing request sent by the User, the challenge information sent by the third-party public auditing TPA, the certification information returned by the CS and verified by the TPA, the data information of the user is not leaked in the verification process through the mask technology twice. The method provided by the invention is based on lattice difficulty problems, can effectively resist quantum computing attacks, and ensures the robustness of the scheme.

Description

Technical Field

[0001] The present invention relates to the field of data storage, and in particular to a cloud storage integrity detection method and system based on identity on a grid. Background Art

[0002] In 2007, the Provable Data Possession (PDP) model was proposed, which provided a theoretical basis for data integrity and availability, allowing users to verify the integrity of their data without directly accessing the data. In the same year, the concept and formal model of Proof of Retrievability (POR) were proposed. The sentinel-based POR verification mechanism can not only identify whether remote data is damaged but also recover damaged data files. Although the PDP and POR models provide effective solutions for data integrity and availability verification, the audit work of these models needs to be completed by users themselves, which will impose a burden on users with limited resources. In order to reduce the computing burden of users, subsequent research proposed a third-party public auditing (TPA) mechanism, which allows TPA to verify the integrity of data stored in cloud servers on behalf of users. Users can rely on the audit results of TPA to confirm the integrity of data without downloading the data.

[0003] In addition, with the development of quantum computers, traditional public key cryptography faces the risk of being cracked by quantum computers, thus threatening the security of the above-mentioned audit scheme. To meet this challenge, Post-Quantum Cryptography (PQC) has gradually become a research hotspot. Among them, lattice cryptography has attracted much attention due to its strong security and computational efficiency. The Small Integer Solution (SIS) and Learning With Errors (LWE) problems on lattices are still considered difficult in the environment of quantum computing, which gives lattice cryptography a significant advantage in resisting quantum computing.

[0004] The identity-based cryptographic system solves the problem of expensive certificate management based on PKI technology to a certain extent. In the identity-based cryptographic system scheme, the user's identity, such as name, ID number, email address, etc., is regarded as a public key, and the user's private key is generated for the user by PKG. The existing lattice cloud storage integrity detection scheme is usually based on the small integer solution problem on the ideal lattice, so that the scheme can still maintain a high security in the quantum computing environment. And design a new label generation algorithm and private key extraction algorithm, and the user uses the private key to calculate the file block label. The design of this scheme does not consider the problem of data information leakage during the integrity proof process. In view of the defects of the existing cloud storage integrity audit scheme, the existing technology proposes a new lattice-based identity-based remote data integrity audit protocol. The scheme supports third-party public audits and does not disclose information about user stored data during the audit process. Through the study of the existing scheme, it is found that it cannot provide privacy protection for messages during the authentication process. The cloud server can forge legal proofs and pass the third-party audit public verification without completely saving the data uploaded by the user. Summary of the invention

[0005] In view of the risk of traditional public key cryptography being cracked by quantum computers and the problem of user data information leakage in the third-party public audit process, the present invention proposes a cloud storage integrity detection method and system based on identity on a grid to solve the problems raised in the above background technology. The technical solution provided by the present invention is as follows: In a first aspect, the present invention proposes a cloud storage integrity detection method based on identity on a grid, comprising the following steps: S1, the key generation center PKG generates system parameters in the form of a lattice password, and based on the system parameters, the key generation center PKG generates the private keys of the user User and the cloud server CS; S2, user User divides the data file into blocks, signs it, and uploads it to the cloud server CS; S3, user User sends an audit request, the third-party public audit TPA generates and sends challenge information, the cloud server CS generates and returns proof information and is verified by the third-party public audit TPA. The verification process uses double masking technology to judge the integrity of the data by whether two equations and two inequalities are true or not.

[0006] Preferably, the process of the key generation center PKG generating system parameters is: S111, select two prime numbers q and p , two integers m、n and real numbers g ,in , poly and oh expressn The relevant time complexity satisfies the following relationship:

[0007]

[0008]

[0009] S112, the key generation center PKG selects four hash functions, which are respectively expressed as follows:

[0010]

[0011]

[0012]

[0013] S113, the key generation center PKG uses the trapdoor generation algorithm to generate the matrix Passive Base T A , A It is a system common parameter. T A Is the master private key of the system.

[0014] Preferably, the key generation process is: S121, according to the system parameters, the user User and the cloud server CS respectively send the identity information id u and id s Sent to the key generation center PKG, which generates the public key of the user User B and the public key of the cloud server CS Q , expressed as:

[0015]

[0016] S122, the key generation center PKG uses the NewBasisDel algorithm to generate the private keys of the user User and the cloud server CS T id , T Q , expressed as:

[0017]

[0018] NewBasisDel is a probabilistic polynomial time algorithm with parameter s satisfying the inequality and ; S123, the key generation center PKG sends the private key to the user User and the cloud server CS through a secure channel for storage.

[0019] Preferably, the process in which the user User divides the data file into blocks, signs it, and uploads it to the cloud server CS is as follows: S21, user User uses any digital signature algorithm, and its signature public and private keys are (spk,ssk) , using the SamplePre algorithm to generate short vectors , β satisfy , expressed as:

[0020] SamplePre is also a probabilistic polynomial-time algorithm with parameters Satisfy the inequality ; S22, calculation , user User will data file F Divided into data blocks, i.e. , using the signature private key ssk For Message name ‖ Q’ Generate a signature, name Name the data file and set the data file F Tags , User calculation ; S23, for data blocks , and use your public key B Public key with cloud server Q Combine, calculate , user User calculates the inner product , and set ; S24, User calculation data block m i Tags ,parameter Satisfy the inequality , the label set of all data blocks , and eventually Send to the cloud server and delete the locally stored files F .

[0021] Preferably, the third-party public audit TPA generates challenge information including: Third-party public audit TPA definition set and , ; For the collection I Any element in i , randomly select a matrix Generate Challenge Information , and sends the challenge information to the cloud server CS.

[0022] Preferably, the certification information returned by the cloud server CS includes: The cloud server CS selects the data block based on the challenge information received and the corresponding labels And calculate , randomly select a vector , using the SamplePre algorithm to generate short vectors x , expressed as:

[0023] Cloud Server CS Computing , and , generate proof information Sent to third-party public audit TPA.

[0024] Preferably, the third-party public audit TPA verification process includes: S31, after receiving the certification information from the cloud server CS, the third-party public audit TPA uses the user User signature public key spk Verify Tags t If it is legal, continue to verify; S32, calculation ,make ; S33, calculation ,calculate ; S34, verify equation and Is it true, and the inequality and Whether it is true; if both are true, the third-party public auditor TPA accepts the evidence and believes that the information is legal; otherwise, it proves that the information is illegal and the integrity of the stored data is damaged.

[0025] In a second aspect, the present invention proposes a cloud storage integrity detection system based on identity on a grid, comprising the following modules: The key distribution module is used to generate the private keys of the user User and the cloud server CS according to the system parameters generated by the key generation center PKG, and complete the key distribution; The data upload module is used to divide and sign the data files according to the user User and upload them to the cloud server CS; The verification module is used to issue an audit request based on the user User, the third-party public audit TPA issues a challenge message, the cloud server CS returns the proof information and is verified by the third-party public audit TPA. Through the double masking technology, it is ensured that the user's data information is not leaked during the verification process.

[0026] Compared with the prior art, the beneficial effects achieved by the present invention are: The method of the present invention is based on the ISIS problem and the SIS problem on the lattice, and can effectively resist quantum computing attacks; by dividing the file into data blocks, the data blocks are smaller, the computing efficiency is improved, and the computing cost is reduced; during the third-party audit, the double masking technology is used to ensure that the user's data information is not leaked during the verification process, provide privacy protection for the message, and prevent the cloud server from forging legal proof to pass the third-party audit public verification without completely saving the data uploaded by the user. The method proposed by the present invention has correctness, privacy, robustness, and anti-quantum security. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings: Figure 1 It is a schematic diagram of a model of the system of the present invention; Figure 2 It is an interactive schematic diagram of the algorithm of the present invention. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] See also Figure 1-Figure 2 , the present invention provides a technical solution:

[0030] Embodiment 1: A cloud storage integrity detection method based on identity on a grid, such as Figure 1 As shown, the following steps are included: S1, the key generation center PKG generates system parameters in the form of a lattice password. According to the system parameters, the key generation center PKG generates the private keys of the user User and the cloud server CS.

[0031] The process of the key generation center PKG generating system parameters is as follows: S111, select two prime numbers q and p , two integers m、n and real numbers g ,in , poly and oh express n The relevant time complexity satisfies the following relationship:

[0032]

[0033]

[0034] S112, the key generation center PKG selects four hash functions, which are respectively expressed as follows:

[0035]

[0036]

[0037]

[0038] S113, the key generation center PKG uses the trapdoor generation algorithm to generate the matrix Passive Base T A , A It is a system common parameter. T A Is the master private key of the system.

[0039] The process of key generation center PKG generating keys is as follows: S121, according to the system parameters, the user User and the cloud server CS respectively send the identity information id u and id s Sent to the key generation center PKG, which generates the public key of the user User B and the public key of the cloud server CS Q , expressed as:

[0040]

[0041] Hash functions There are many options, such as the common and more secure SHA-1 algorithm, SHA-256 algorithm, SM3 algorithm, etc. By calling these algorithms to get a hash value of a certain length, you can generate it in the following way m×m Column matrix: matrix R u As an example, an upper triangular matrix is ​​constructed, whose diagonal elements are all 1, followed by the obtained hash values, and the rest are filled with 0.

[0042] S122, the key generation center PKG uses the NewBasisDel algorithm to generate the private keys of the user User and the cloud server CS T id , T Q , expressed as:

[0043]

[0044] NewBasisDel is a probabilistic polynomial time algorithm with parameter s satisfying the inequality and , T id , T Q They are and Short base.

[0045] S123, the key generation center PKG sends the private key to the user User and the cloud server CS through a secure channel for storage.

[0046] S2, user User divides the data file into blocks, signs it, and uploads it to the cloud server CS. The specific process is as follows: S21, user User uses any digital signature algorithm, and its signature public and private keys are (spk,ssk) , using the SamplePre algorithm to generate short vectors , β satisfy , expressed as:

[0047] The SamplePre algorithm first selects a random vector by linear algebra ,satisfy Then the algorithm Get a Gaussian distribution Sample d , where the parameters Satisfy the inequality , according to the equation Get vector .

[0048] S22, calculation , user User will data file F Divided into data blocks, i.e. , using the signature private key ssk For Message name ‖ Q’ Generate a signature, name Name the data file and set the data file F Tags , User calculation ; S23, for data blocks , and use your public key B Public key with cloud server Q Combine, calculate , user User calculates the inner product , and set ; S24, User calculation data block m i Tags ,parameter Satisfy the inequality , the label set of all data blocks , and eventually Send to the cloud server and delete the locally stored files F .

[0049] S3, such as Figure 2 As shown, the user User issues an audit request, the third-party public audit TPA generates and issues a challenge message, the cloud server CS generates and returns the proof information and is verified by the third-party public audit TPA, and the verification process uses double masking technology. Specifically, in the data integrity verification stage, the third-party public audit TPA determines the integrity of the data by checking whether two equations and two inequalities are true or not.

[0050] The third-party public audit TPA generates challenge information including: Third-party public audit TPA definition set and , ; For the collection I Any element in i , randomly select a matrix Generate Challenge Information , and sends the challenge information to the cloud server CS.

[0051] The cloud server CS returns the following certification information: The cloud server CS selects the data block based on the challenge information received and the corresponding labels And calculate , randomly select a vector , using the SamplePre algorithm to generate short vectors x , expressed as:

[0052] Cloud Server CS Computing , and , generate proof information Sent to third-party public audit TPA.

[0053] Among them, the vector x right β and u c The value of introduces an error. Due to the difficulty of the LWE problem in lattice cryptography, the third-party public audit TPA cannot calculate the data block through the proof information, thereby ensuring the privacy protection of user information.

[0054] The third-party public audit TPA verification process includes: S31, after receiving the certification information from the cloud server CS, the third-party public audit TPA uses the user User signature public key spk Verify Tags t If it is legal, continue to verify; S32, calculation ,make ; S33, calculation ,calculate ; S34, verify equation and Is it true, and the inequality and Whether it is true; if both are true, the third-party public auditor TPA accepts the evidence and believes that the information is legal; otherwise, it proves that the information is illegal and the integrity of the stored data is damaged.

[0055] According to the ISIS problem and SIS problem in lattice cryptography, if the cloud server CS does not completely save the data files uploaded by the user User F and its signature collection ϕ , first select ec and oh The value of can be transformed into the above verification equation .and u c ’ is a small value. To calculate the u c ’ The value of , i.e., the ISIS problem, is computationally infeasible. Therefore, it is ensured that the cloud server can only pass the TPA verification if it has completely stored the data files uploaded by the user and their signature sets, preventing the cloud server from forging proofs.

[0056] Embodiment 2: A cloud storage integrity detection system based on identity on a grid, such as Figure 1 As shown, it includes the following modules: The key distribution module is used to generate the private keys of the user User and the cloud server CS according to the system parameters generated by the key generation center PKG, and complete the key distribution; The data upload module is used to divide and sign the data files according to the user User and upload them to the cloud server CS; The verification module is used to issue an audit request based on the user User, the third-party public audit TPA issues a challenge message, the cloud server CS returns the proof information and is verified by the third-party public audit TPA. Through the double masking technology, it is ensured that the user's data information is not leaked during the verification process.

[0057] Those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, or of course by hardware. Based on this understanding, the above technical solution can be essentially or in other words, the part that contributes to the prior art can be embodied in the form of a software product, which can be stored in a computer-readable storage medium, such as ROM / RAM, a magnetic disk, an optical disk, etc., and includes a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiment.

[0058] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention is described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A cloud storage integrity detection method based on identity on a grid, characterized in that: The following steps are involved: S1, the key generation center PKG generates system parameters in the form of a lattice password, and based on the system parameters, the key generation center PKG generates the private keys of the user User and the cloud server CS; S2, user User divides the data file into blocks, signs it, and uploads it to the cloud server CS; S3, user User sends an audit request, the third-party public audit TPA generates and sends challenge information, the cloud server CS generates and returns proof information and is verified by the third-party public audit TPA. The verification process uses double masking technology to judge the integrity of the data by whether two equations and two inequalities are true or not.

2. According to claim 1, a cloud storage integrity detection method based on identity on a grid is characterized in that: The process of the key generation center PKG generating system parameters is as follows: S111, select two prime numbers q and p , two integers m、n and real numbers ζ ,in , poly and ω express n The relevant time complexity satisfies the following relationship: ； ； ； S112, the key generation center PKG selects four hash functions, which are respectively expressed as follows: ； ； ； ； S113, the key generation center PKG uses the trapdoor generation algorithm to generate the matrix Passive Base T A , A It is a system common parameter. T A Is the master private key of the system.

3. The identity-based cloud storage integrity detection method according to claim 2, characterized in that: The key generation process is: S121, according to the system parameters, the user User and the cloud server CS respectively send the identity information id u and id s Sent to the key generation center PKG, which generates the public key of the user User B and the public key of the cloud server CS Q , expressed as: ； ； S122, the key generation center PKG uses the NewBasisDel algorithm to generate the private keys of the user User and the cloud server CS T id , T Q , expressed as: ； ； NewBasisDel is a probabilistic polynomial time algorithm with parameter s satisfying the inequality and ; S123, the key generation center PKG sends the private key to the user User and the cloud server CS through a secure channel for storage.

4. The identity-based cloud storage integrity detection method according to claim 3 is characterized in that: The process of user User dividing the data file into blocks, signing it, and uploading it to the cloud server CS is as follows: S21, user User uses any digital signature algorithm, and its signature public and private keys are (spk,ssk) , using the SamplePre algorithm to generate short vectors , β satisfy , expressed as: ； SamplePre is also a probabilistic polynomial-time algorithm with parameters Satisfy the inequality ; S22, calculation , user User will data file F Divided into data blocks, i.e. , using the signing private key ssk For Message name ‖ Q’ Generate a signature, name Name the data file and set the data file F Tags , User calculation ; S23, for data blocks , and use your public key B Public key with cloud server Q Combine, calculate , user User calculates the inner product , and set ; S24, User calculation data block m i Tags ,parameter Satisfy the inequality , the label set of all data blocks , and eventually Send to the cloud server and delete the locally stored files F .

5. The identity-based cloud storage integrity detection method according to claim 4, characterized in that: The third-party public audit TPA generates challenge information including: Third-party public audit TPA definition set and , ; For the collection I Any element in i , randomly select a matrix Generate Challenge Information , and sends the challenge information to the cloud server CS.

6. The identity-based cloud storage integrity detection method according to claim 5, characterized in that: The cloud server CS returns the certification information including: The cloud server CS selects the data block based on the challenge information received and the corresponding labels And calculate , randomly select a vector , using the SamplePre algorithm to generate short vectors ξ , expressed as: ； Cloud Server CS Computing , and , generate proof information Sent to third-party public audit TPA.

7. The identity-based cloud storage integrity detection method according to claim 6, characterized in that: The third-party public audit TPA verification process includes: S31, after receiving the certification information from the cloud server CS, the third-party public audit TPA uses the user User signature public key spk Verify Tags τ If it is legal, continue to verify; S32, calculation ,make ; S33, calculation ,calculate ; S34, verify equation and Is it true, and the inequality and Whether it is true; if both are true, the third-party public auditor TPA accepts the evidence and believes that the information is legal; otherwise, it proves that the information is illegal and the integrity of the stored data is damaged.

8. A cloud storage integrity detection system based on identity on a grid, the system implementing the detection method according to any one of claims 1 to 7, characterized in that: Includes the following modules: The key distribution module is used to generate the private keys of the user User and the cloud server CS according to the system parameters generated by the key generation center PKG, and complete the key distribution; The data upload module is used to divide and sign the data files according to the user User and upload them to the cloud server CS; The verification module is used to issue an audit request based on the user User, the third-party public audit TPA issues a challenge message, the cloud server CS returns the proof information and is verified by the third-party public audit TPA. Through the double masking technology, it is ensured that the user's data information is not leaked during the verification process.

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