Identity-based cloud storage data integrity auditing method

Abstract

The present application relates to a kind of cloud storage data integrity auditing method based on identity.The method includes generating system parameter, user private key extraction, private key verification, generating label, verifying data block integrity, generating challenge information, generating audit proof challenge information and integrity audit.Compared with prior art, the present application is based on identity-based cryptography system design, effectively avoids complex certificate management;In the stage of generating data block label, by the method of pre-processing and selecting a random number to file, effectively avoid the problem that the length of generated data block label is longer than the length of data block itself, and under the premise that user can effectively carry out integrity audit, greatly reduce the calculation complexity of user in generating data block label.

Description

Technical Field

[0001] This invention belongs to the field of data integrity auditing technology in information security, and specifically relates to an identity-based cloud storage data integrity auditing method. Background Technology

[0002] With the rapid development of the internet and the explosive growth of data, cloud storage technology has emerged. Cloud storage is a service provided by cloud computing technology, allowing users to store data on cloud servers, enabling them to access and use their data anytime, anywhere. Data security is a crucial issue in cloud storage technology and one of the most pressing concerns for users. Because cloud storage stores data on cloud servers rather than local storage devices, the security, integrity, and availability of the data all need to be guaranteed. Therefore, efficiently auditing the integrity of data stored in the cloud is a key problem that needs to be addressed.

[0003] Existing integrity auditing technologies mainly include two types: Proof of Data Possession (PDP) and Proof of Data Retrievability (PoR). In 2007, Ateniese et al. proposed the Proof of Data Possession (PDP) model and designed an integrity auditing scheme based on the RSA cryptosystem. In the same year, Juels and Kaliski proposed the Proof of Retrievability (PoR) model, which mainly uses error-correcting codes and message authentication mechanisms to ensure the integrity and recoverability of remote data files. Later, Shacham and Waters proposed a BLS-based integrity auditing scheme based on the PoR model.

[0004] Among the technologies mentioned above, the PDP model has the problem that the space occupied by storing data block labels is larger than the space required for the data block itself. From the perspective of cloud service providers (CSPs) storing as much user data as possible, this technology is not ideal. The PoR model solves this problem well, and the integrity audit scheme based on BLS generates a shorter signature for the data block than the integrity audit scheme based on RSA cryptography in the PDP model. However, it requires higher computational cost when generating data block labels.

[0005] Following the work of the aforementioned individuals, researchers have proposed numerous integrity auditing schemes. However, most integrity auditing schemes are based on Public Key Infrastructure (PKI), which faces various issues related to certificate management, including certificate revocation, storage, distribution, and verification. In other identity-based cryptographic systems, schemes modeled on PDP still suffer from excessively long block tag lengths, while schemes modeled on PoR still face the problem of high computational costs in generating block tags. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of existing technologies by reducing the computational complexity of generating file tags for users, while ensuring that users can effectively perform integrity audits, and to provide an identity-based cloud storage data integrity auditing method.

[0007] To achieve the above objectives, the technical solution of the present invention is: an identity-based cloud storage data integrity auditing method, comprising the following steps:

[0008] (1) Generate system parameters: The key generation center PKG executes the initialization algorithm to generate public parameter param, master public key mpk and master private key msk;

[0009] (2) User Private Key Extraction: The Key Generation Center (PKG) runs a private key extraction algorithm, taking user U's identity ID, master private key msk, and public parameter param as input, and outputting the private key s corresponding to user U's identity ID. ID And send it to user U through a secure channel;

[0010] (3) Private key verification: User U runs the key verification algorithm to verify the received private key s. ID The correctness;

[0011] (4) Generate labels: User U first preprocesses file F, and then runs the data block label generation algorithm to generate labels {σ} corresponding to the data blocks. i} 1≤i≤n User U generates a tag τ corresponding to file F using a standard signature algorithm, and then assigns file F and data block tags {σ} to the tag τ. i} 1≤i≤n The tag τ corresponding to file F is sent to the cloud service provider CSP for storage. After the cloud service provider CSP completes data integrity verification, user U deletes the local file F and the data block tag {σ}. i} 1≤i≤n ;

[0012] (5) Verify data block integrity: The cloud service provider CSP receives the file F and data block tag {σ} from user U. i} 1≤i≤nAfter assigning the label τ to file F, the validity of the label τ is first verified. If valid, the data block label σ is then used. i Verify the corresponding data block m i If the data block and its tag are verified to be valid, the data block and its tag will be stored. Otherwise, feedback will be sent to user U, asking them to resend the data block and its tag that failed verification. If the tag τ corresponding to file F is invalid, user U's storage request will be terminated.

[0013] (6) Generating Challenge Information: User U sends the tag τ corresponding to file F to the third-party auditor TPA, entrusting it to perform an integrity audit on the user's data stored in the cloud service provider CSP; after receiving the entrustment, the third-party auditor TPA first verifies the validity of the file tag τ. If it is valid, it generates a set of challenge information. in For a subset of the set [1, n], challenge a random value. And send it to the cloud service provider CSP; otherwise, terminate user U's delegation request.

[0014] (7) Generate audit verification response information: After receiving the challenge information, the cloud service provider CSP generates audit verification response information based on the challenged data block and the corresponding data block label, and returns the audit verification response information to the third-party auditor TPA;

[0015] (8) Integrity audit: After receiving the audit certification response information, the third-party auditor TPA uses the system parameter param, the user U's identity ID, and the user U's publicly disclosed verification value to verify the correctness of the audit certification response information.

[0016] In one embodiment of the present invention, step (1) generates system parameters in the following manner:

[0017] (1.1) The key generation center PKG selects a large prime number p and a prime field. Multiplication group: Three multiplicative cyclic groups of order p: An asymmetric bilinear mapping: An isomorphic mapping: Selecting the cyclic group Generators: Cyclic group Generators: calculate Choose two collision-resistant hash functions: Choose a standard signature algorithm SSig(·);

[0018] (1.2) The key generation center (PKG) is randomly selected. Use the system's master private key msk and calculate the system's master public key.

[0019] (1.3) The Key Generation Center (PKG) publishes public parameters.

[0020] In one embodiment of the present invention, step (2) extracts the user's private key in the following manner:

[0021] (2.1) The key generation center PKG calculates the corresponding private key for user U based on user U's identity ID.

[0022] (2.2) The key generation center PKG will generate the private key s corresponding to user U's identity ID. ID Sent to user U via a secure channel.

[0023] In one embodiment of the present invention, step (3) verifies the user's private key in the following manner:

[0024] (3.1) User U receives private key s ID Then, calculate Then verify the equation. Does it hold true? If it does, then it means s ID It is the private key corresponding to user U's identity ID; otherwise, user U will request a new private key from the key generation center PKG.

[0025] (3.2) User U randomly generates a public-private key pair for the standard signature algorithm SSig(·).

[0026] In one embodiment of the present invention, step (4) generates a label in the following manner:

[0027] (4.1) User U first divides file F into n data blocks, that is in Indicates that there is Each element domain The elements on the data block are then divided into... Each sector, i.e. User U randomly selects an identifier ∈ {0, 1} * As an identifier for file F;

[0028] (4.2) User U selection random numbers Then generate pairs The promise of a random number

[0029] (4.3) User U selects a random number calculate Then, each data block is generated using one's own private key. Tags:

[0030]

[0031] (4.4) User U calculation Then, the standard signature algorithm is used to generate the tag for file F.

[0032] (4.5) User U will assign labels {σ1, ..., σ2, ..., σ3, ..., σ4, ..., σ5, ..., σ6, ..., σ7, ..., σ8, ..., σ9, ..., σ1 ... n The data is sent to the cloud service provider (CSP). After the CSP completes the data integrity verification, the user then deletes the data from local storage.

[0033] In one embodiment of the present invention, step (5) verifies the integrity of the data block in the following manner:

[0034] (5.1) The cloud service provider CSP receives the file F and data block tag {σ} from user U. i} 1≤i≤n After tag τ corresponding to file F, the public key of the standard signature algorithm generated by user U is first used. Verify the file tag τ If valid, the cloud service provider (CSP) parses τ0 to obtain the file identifier, the number of data blocks n, and the number of sectors in the data blocks. The promise of a random number and two verification values ​​h′ ID and h″ ID Otherwise, the cloud service provider (CSP) will terminate user U's storage request;

[0035] (5.2) The cloud service provider (CSP) verifies each data block. The integrity of the equation is verified by judging its validity.

[0036]

[0037] Is it valid?

[0038] (5.3) If the equation is true, the cloud service provider CSP stores the verified data block and its corresponding tag; if the equation is false, feedback is given to user U, asking him to send the database that failed verification and its corresponding tag.

[0039] In one embodiment of the present invention, step (6) generates challenge information in the following manner:

[0040] (6.1) User U sends the file tag τ to the third-party auditor TPA and entrusts the third-party auditor TPA to perform an integrity audit;

[0041] (6.2) The third-party auditor TPA uses the public key of the standard signature algorithm generated by user U. Verify the file tag τ Validity: If valid, the third-party auditor TPA parses τ0 to obtain the file identifier, the number of data blocks n, and the number of sectors in each data block. The promise of a random number and two verification values ​​h′ ID and h″ ID Otherwise, the third-party auditor TPA will terminate user U's engagement request;

[0042] (6.3) The third-party auditor (TPA) randomly selects a subset of the set [1, n]. and corresponding challenge random values Form a set of challenge information And send it to the cloud service provider CSP.

[0043] In one embodiment of the present invention, step (7) generates audit verification response information in the following manner:

[0044] (7.1) Cloud service providers (CSPs) receive a set of challenges from third-party auditors (TPAs). Then, calculate the challenged data block. Aggregation with corresponding data block labels

[0045] (7.2) The cloud service provider (CSP) will provide audit verification response information. Send it to the third-party auditor, TPA.

[0046] In one embodiment of the present invention, step (8) is performed on integrity auditing in the following manner:

[0047] (8.1) The third-party auditor (TPA) receives the audit certification response information. Then, verify the equation:

[0048]

[0049] Is it valid?

[0050] (8.2) If the equation is true, the verification is successful and the result is 1, indicating that the data stored by user U in the cloud service provider CSP has not been modified. Otherwise, the result is 0, indicating that the data stored by user U in the cloud service provider CSP has been damaged or modified.

[0051] Compared with the prior art, the present invention has the following beneficial effects:

[0052] (1) The method of the present invention is designed based on an identity-based cryptographic system, which effectively avoids complex certificate management compared to many data integrity auditing schemes based on public key infrastructure (PKI);

[0053] (2) The method of the present invention is based on the PoR model designed by Shacham and Waters. Compared with the data integrity audit scheme designed with the PDP model, it effectively avoids the problem that the length of the generated data block label is longer than the length of the data block itself.

[0054] (3) In the algorithm for generating data block labels, the method of the present invention selects... A random number {u1, ..., u} l}, users generate each data block Only one exponentiation operation is needed when labeling. The computational cost required for a user to generate a data block label has been reduced to the original value. Attached Figure Description

[0055] Figure 1 This is a flowchart of an identity-based cloud storage data integrity auditing method according to the present invention.

[0056] Figure 2 This is a system model diagram of an identity-based cloud storage data integrity auditing method according to the present invention. Detailed Implementation

[0057] To illustrate the technical solutions disclosed in this invention in detail, further descriptions are provided below in conjunction with the accompanying drawings and specific embodiments.

[0058] This invention provides an identity-based cloud storage data integrity auditing method, such as... Figure 2 As shown, the system model involved consists of the following four entities:

[0059] Key Generation Center (PKG): Primarily responsible for generating user private keys, receiving user identity information and generating private keys based on that information, and then transmitting the private keys to the user through a secure channel.

[0060] User: The owner of the data. Each user can store data in a cloud service provider (CSP) and submit a challenge request to the CSP through a third-party auditor (TPA) to verify the integrity of the data stored in the CSP.

[0061] Cloud Service Provider (CSP): Its main functions are to store data and generate audit verification response information. After receiving a challenge from a third-party auditor (TPA), the CSP generates audit verification response information that can prove whether the data is complete and returns it to the TPA.

[0062] Third-party auditor (TPA): Its main function is to interact with users and cloud service providers (CSPs). It receives client requests and generates challenge information to send to the CSP. It interacts with the server, executes data integrity audit verification algorithms, verifies the integrity of the data, and sends the audit results to the user.

[0063] The specific steps described in this invention are as follows:

[0064] (1) Generate system parameters: The key generation center (PKG) executes the initialization algorithm to generate public parameters param, master public key mpk, and master private key msk, as described in the following:

[0065] (1.1) The key generation center PKG selects a large prime number p and a prime field. Multiplication group: Three multiplicative cyclic groups of order p: An asymmetric bilinear mapping: An isomorphic mapping: Selecting the cyclic group Generators: Cyclic group Generators: calculate Choose two collision-resistant hash functions: Choose a standard signature algorithm SSig(·);

[0066] (1.2) The key generation center (PKG) is randomly selected. Use the system's master private key msk and calculate the system's master public key.

[0067] (1.3) The Key Generation Center (PKG) publishes public parameters.

[0068] (2) User Private Key Extraction: The Key Generation Center (PKG) runs a private key extraction algorithm, taking user U's identity ID, master private key msk, and public parameter param as input, and outputting the private key s corresponding to user U's identity ID. TD And it is sent to user U through a secure channel, specifically as follows:

[0069] (2.1) The key generation center PKG calculates the corresponding private key for user U based on user U's identity ID.

[0070] (2.2) The key generation center PKG will generate the private key s corresponding to user U's identity ID. ID Sent to user U via a secure channel.

[0071] (3) Private key verification: User U runs the key verification algorithm to verify the received private key s. ID The correctness is specifically stated as follows:

[0072] (3.1) User U receives private key s ID Then, calculate Then verify the equation. Does it hold true? If it does, then it means s ID It is the private key corresponding to user U's identity ID; otherwise, user U will request a new private key from the key generation center PKG.

[0073] (3.2) User u randomly generates a public-private key pair for the standard signature algorithm SSig(·).

[0074] (4) Generate labels: User U first preprocesses file F, and then runs the data block label generation algorithm to generate labels {σ} corresponding to the data blocks. i} 1≤i≤n User U generates a tag τ corresponding to file F using a standard signature algorithm, and then assigns file F and data block tags {σ} to the tag τ. i} 1≤i≤n The tag τ corresponding to file F is sent to the cloud service provider CSP for storage. After the cloud service provider CSP completes data integrity verification, user U deletes the local file F and the data block tag {σ}. i} 1≤i≤n Specifically, it is described as follows:

[0075] (4.1) User U first divides file F into n data blocks, that is in Indicates that there is Each element domain The elements on the data block are then divided into... Each sector, i.e. User U randomly selects an identifier ∈ {0, 1} * As an identifier for file F;

[0076] (4.2) User U selection random numbers Then generate pairs The promise of a random number

[0077]

[0078] (4.3) User U selects a random number calculate Then, each data block is generated using one's own private key. Tags:

[0079]

[0080] (4.4) User U calculation Then, the standard signature algorithm is used to generate the tag for file F.

[0081] (4.5) User U will assign labels {σ1, ..., σ2, ..., σ3, ..., σ4, ..., σ5, ..., σ6, ..., σ7, ..., σ8, ..., σ9, ..., σ1 ... n The data is sent to the cloud service provider (CSP). After the CSP completes the data integrity verification, the user then deletes the data from local storage.

[0082] (5) Verify data block integrity: The cloud service provider CSP receives the file F and data block tag {σ} from user U. i} 1≤i≤n After assigning the label τ to file F, the validity of the label τ is first verified. If valid, the data block label σ is then used. i Verify the corresponding data block m i The integrity of the data block is verified. If the verification passes, the data block and its tag are stored; otherwise, feedback is sent to user U, requesting them to resend the failed data block and its corresponding tag. If the tag τ corresponding to file F is invalid, user U's storage request is terminated. Specifically:

[0083] (5.1) The cloud service provider CSP receives the file F and data block tag {σ} from user U. i} 1≤i≤n After tag τ corresponding to file F, the public key of the standard signature algorithm generated by user U is first used. Verify the file tag τ If valid, the cloud service provider (CSP) parses τ0 to obtain the file identifier, the number of data blocks n, and the number of sectors in the data blocks. The promise of a random number and two verification values ​​h′ ID and h″ ID Otherwise, the cloud service provider (CSP) will terminate user U's storage request;

[0084] (5.2) The cloud service provider (CSP) verifies each data block. The integrity of the equation is verified by judging its validity.

[0085]

[0086] Is it valid?

[0087] (5.3) If the equation is true, the cloud service provider CSP stores the verified data block and its corresponding tag; if the equation is false, feedback is given to user U, asking him to send the database that failed verification and its corresponding tag.

[0088] (6) Generating Challenge Information: User U sends the tag τ corresponding to file F to the third-party auditor TPA, entrusting it to perform an integrity audit on the user's data stored in the cloud service provider CSP; after receiving the entrustment, the third-party auditor TPA first verifies the validity of the file tag τ. If it is valid, it generates a set of challenge information. And send it to the cloud service provider CSP; otherwise, terminate user U's delegation request, specifically as follows:

[0089] (6.1) User U sends the file tag τ to the third-party auditor TPA and entrusts the third-party auditor TPA to perform an integrity audit;

[0090] (6.2) The third-party auditor TPA uses the public key of the standard signature algorithm generated by user U. Verify the file tag τ Validity: If valid, the third-party auditor TPA parses τ0 to obtain the file identifier, the number of data blocks n, and the number of sectors in each data block. The promise of a random number and two verification values ​​h′ ID and h″ ID Otherwise, the third-party auditor TPA will terminate user U's engagement request;

[0091] (6.3) The third-party auditor (TPA) randomly selects a subset of the set [1, n]. and corresponding challenge random values Form a set of challenge information And send it to the cloud service provider CSP.

[0092] (7) Generate Audit Verification Response Information: After receiving the challenge information, the cloud service provider (CSP) generates audit verification response information based on the challenged data block and its corresponding data block tag, and returns the audit verification response information to the third-party auditor (TPA). Specifically, this is described as follows:

[0093] (7.1) Cloud service providers (CSPs) receive a set of challenges from third-party auditors (TPAs). Then, calculate the challenged data block. Aggregation with corresponding data block labels

[0094] (7.2) The cloud service provider (CSP) will provide audit verification response information. Send it to the third-party auditor, TPA.

[0095] (8) Integrity Audit: After receiving the audit certification response information, the third-party auditor TPA uses the system parameter param, the user U's identity ID, and the user U's publicly disclosed verification value to verify the correctness of the audit certification response information, specifically as follows:

[0096] (8.1) The third-party auditor (TPA) receives the audit certification response information. Then, verify the equation:

[0097]

[0098] Is it valid?

[0099] (8.2) If the equation is true, the verification is successful and the result is 1, indicating that the data stored by user U in the cloud service provider CSP has not been modified or destroyed. Otherwise, the result is 0, indicating that the data stored by user U in the cloud service provider CSP has been destroyed or modified.

[0100] In this embodiment, user U's private key s ID The correctness verification process is as follows:

[0101]

[0102] In this embodiment, a single data block The correctness verification process is as follows:

[0103]

[0104] The correctness derivation process of the integrity audit in this embodiment is as follows:

[0105] because

[0106]

[0107] Therefore, the correctness verification process for integrity auditing is as follows:

[0108]

[0109] The above description is merely a preferred embodiment of the present invention. It should be understood that the present invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the concept described herein through the above teachings or related technologies or knowledge. Modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the protection scope of the appended claims.

Claims

1. An identity-based cloud storage data integrity auditing method, characterized in that, Includes the following steps: (1) Generate system parameters: The key generation center PKG executes the initialization algorithm to generate common parameters. Master key and the master private key The details are as follows: (1.1) The key generation center PKG selects a large prime number. A prime domain Multiplication group: Three orders are large prime numbers Multiplication cyclic group: , , An asymmetric bilinear mapping: An isomorphic mapping: ; Selecting the cyclic group Generators: Cyclic group Generators: ,calculate ; Choose two collision-resistant hash functions: , ; Choose a standard signature algorithm ; (1.2) The key generation center (PKG) is randomly selected. As the system's master and private keys And calculate the system master public key. ; (1.3) The Key Generation Center (PKG) publishes public parameters. ; (2) User private key extraction: The key generation center PKG runs a private key extraction algorithm, using the identity of user U. Master private key and common parameters As input, output user U's identity. corresponding private key And it is sent to user U via a secure channel; specifically as follows: (2.1) The key generation center PKG determines the identity of user U. Calculate its corresponding private key ; (2.2) The key generation center PKG will identify user U. corresponding private key Send to user U via a secure channel; (3) Private key verification: User U runs the key verification algorithm to verify the received private key. The correctness of the statement is as follows: (3.1) User U receives the private key Then, calculate , Then verify the equation. Is it true? If it is true, then it means... It is user U's identity The corresponding private key; otherwise, user U will request a new private key from the key generation center PKG. (3.2) User U randomly generates a pair of standard signature algorithms public and private key pairs ; (4) Generate tags: User U first selects the file Perform preprocessing, and then run the data block label generation algorithm to generate labels for the data blocks. ; User U generates a file using a standard signature algorithm. Corresponding tags Then the file Data block labels and documents Corresponding tags The data is sent to the cloud service provider (CSP) for storage. After the CSP completes data integrity verification, user U deletes the local file. and data block labels The details are as follows: (4.1) User U first puts the file Divided into One data block, i.e. ,in Indicates that there is Each element domain The elements on the data block are then divided into... Each sector, i.e. User U randomly selects one As a document The identifier; (4.2) User U selection random numbers Then generate a pair The promise of a random number ; (4.3) User U selects a random number ,calculate Then, each data block is generated using its own private key. Tags: (4.4) User U calculation Then, a file is generated using a standard signature algorithm. tags ; (4.5) User U will send the file Labels of all data blocks The data is sent to the cloud service provider CSP. After the cloud service provider CSP completes the data integrity verification, user U deletes the data from local storage. (5) Verify data block integrity: The cloud service provider CSP receives the file from user U. Data block labels and documents Corresponding tags Then, first verify the file. Corresponding tags The validity of the data is verified, and if valid, it is verified via the data block label. Verify the corresponding data block The integrity of the data block is checked. If the verification passes, the data block and its tag are stored; otherwise, feedback is sent to user U, requesting them to resend the failed data block and its corresponding tag. If the file... Corresponding tags If invalid, terminate user U's storage request; (6) Generate challenge information: User U will send the file Corresponding tags The request is sent to a third-party auditor (TPA), commissioning them to perform an integrity audit of the user's data stored in the cloud service provider (CSP). Upon receiving the request, the TPA first verifies the file tags. If the validity is verified, a set of challenge information is generated. ,in For set A subset of, challenging random values And send it to the cloud service provider CSP; otherwise, terminate user U's delegation request. (7) Generate audit verification response information: After receiving the challenge information, the cloud service provider CSP generates audit verification response information based on the challenged data block and the corresponding data block label, and returns the audit verification response information to the third-party auditor TPA; (8) Integrity Audit: After receiving the audit certification response information, the third-party auditor (TPA) uses system parameters... User U's identity The correctness of the audit verification response information is verified using the verification value disclosed by user U.

2. The identity-based cloud storage data integrity auditing method according to claim 1, characterized in that, Step (5) verifies the integrity of the data block in the following manner: (5.1) The cloud service provider (CSP) receives the file from user U. Data block labels and documents Corresponding tags Then, the public key of the standard signature algorithm generated by user U is used first. Verify file tags In Validity; if valid, cloud service provider CSP resolution. Get the file identifier Number of data blocks Number of sectors in a data block , The promise of a random number and two verification values and Otherwise, the cloud service provider (CSP) will terminate user U's storage request; (5.2) The cloud service provider (CSP) verifies each data block. The integrity of the equation is verified by judging its validity. Is it valid? (5.3) If the equation is true, the cloud service provider CSP stores the verified data block and its corresponding tag; if the equation is false, feedback is given to user U, asking him to send the database that failed verification and its corresponding tag.

3. The identity-based cloud storage data integrity auditing method according to claim 2, characterized in that, Step (6) generates challenge information in the following manner: (6.1) User U will tag the file Send it to a third-party auditor (TPA) and entrust the TPA to conduct an integrity audit. (6.2) The third-party auditor TPA uses the public key of the standard signature algorithm generated by user U. Verify file tags In Validity; if valid, third-party auditor TPA analysis. Get the file identifier Number of data blocks Number of sectors in a data block , The promise of a random number and two verification values and Otherwise, the third-party auditor TPA will terminate user U's engagement request; (6.3) Third-party auditors (TPA) randomly select a set. subset of and corresponding challenge random values This forms a set of challenge information. And send it to the cloud service provider CSP.

4. The identity-based cloud storage data integrity auditing method according to claim 3, characterized in that, Step (7) generates the audit verification response information as follows: (7.1) Cloud service providers (CSPs) receive a set of challenges from third-party auditors (TPAs). Then, calculate the challenged data block. Aggregation with corresponding data block labels ; (7.2) The cloud service provider (CSP) will provide audit verification response information. Send it to the third-party auditor, TPA.

5. The identity-based cloud storage data integrity auditing method according to claim 4, characterized in that, The integrity audit is performed in the following manner: (8.1) The third-party auditor (TPA) receives the audit certification response information. Then, verify the equation: Is it valid? (8.2) If the equation is true, the verification is successful and the result is 1, indicating that the data stored by user U in the cloud service provider CSP has not been modified. Otherwise, the result is 0, indicating that the data stored by user U in the cloud service provider CSP has been corrupted or modified.

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