Cloud data integrity auditing method, device and equipment and storage medium

Abstract

The invention discloses a cloud data integrity auditing method, device and equipment and a storage medium, and is applied to the field of data security, and the method comprises the steps: generating challenge information when an auditing instruction of to-be-audited data is received, and sending the challenge information to a cloud; to-be-audited data and a corresponding file authenticator are stored in the cloud; obtaining proof information calculated by the cloud according to the challenge information, a file authenticator corresponding to the to-be-audited data and the to-be-audited data; and obtaining a homomorphic verifiable label corresponding to the to-be-audited data from the cloud, and determining whether the to-be-audited data is complete or not according to the proof information and the homomorphic verifiable label. According to the method, the cloud data integrity is audited based on the identity cryptography algorithm, and the transmission data volume during auditing is irrelevant to the scale of the audited data, so that high bandwidth cost is not needed, and the calculation overhead is reduced.

Description

Technical Field

[0001] The present invention relates to the field of data security, and in particular to a cloud data integrity audit method, device, equipment and storage medium. Background Art

[0002] When users interact with cloud data (cloud data), data integrity may be destroyed due to network failures, hacker attacks, etc. Cloud storage may also threaten data integrity due to natural disasters, administrator misconduct, etc. In order to protect the integrity of cloud data, cloud data needs to be audited to detect data anomalies in a timely manner.

[0003] Currently, cloud data integrity verification is usually implemented based on hash functions, where the TPA (Third party auditor) must first download all cloud data to be audited from the cloud, then calculate their hash values, and compare them with the locally saved hash values ​​to obtain the audit results. Due to the huge amount of cloud data, this method will result in high bandwidth costs and computing overhead.

[0004] Therefore, how to provide a low-cost cloud data integrity audit method is a technical problem that needs to be solved urgently. Summary of the invention

[0005] In view of this, the purpose of the present invention is to provide a cloud data integrity audit method, device, equipment and storage medium, which solves the problems of high cost, low efficiency and large computational complexity of cloud data integrity verification in the prior art.

[0006] In order to solve the above technical problems, the present invention provides a cloud data integrity audit method, comprising:

[0007] When receiving an audit instruction for the data to be audited, generating challenge information, and sending the challenge information to the cloud; the cloud stores the data to be audited and the corresponding file authentication code;

[0008] Obtaining certification information calculated by the cloud based on the challenge information, the file authentication code corresponding to the data to be audited, and the data to be audited;

[0009] Obtain a homomorphically verifiable tag corresponding to the data to be audited from the cloud, and determine whether the data to be audited is complete based on the proof information and the homomorphically verifiable tag.

[0010] Optionally, obtaining a homomorphically verifiable tag corresponding to the data to be audited from the cloud, and determining whether the data to be audited is complete according to the certification information and the homomorphically verifiable tag, includes:

[0011] Obtaining a homomorphically verifiable tag corresponding to the data to be audited from the cloud;

[0012] Obtaining constituent elements and a public key from the homomorphically verifiable tag;

[0013] Verify the equation based on the component elements, the public key and the certification information Is it correct? Among them, Indicates challenge information. , Represents a random number, Indicates the index information of the data block. represents the random number of the i-th data block, A represents the constituent elements, and Represents two elements of proof information; K represents the public key; represents the hash function; s represents the number of sectors per block; represents a generator;

[0014] If correct, the data to be audited is complete;

[0015] If it is incorrect, the data to be audited is incomplete.

[0016] Optionally, after receiving the audit instruction of the data to be audited, the following is further included:

[0017] Acquire the corresponding homomorphic verifiable tag from the cloud according to the data to be audited;

[0018] A digital signature value is calculated using a digital signature function according to the file name, constituent elements, public key and file tag in the homomorphically verifiable tag;

[0019] If the digital signature value is the same as the digital signature value in the homomorphically verifiable tag, the homomorphically verifiable tag is valid, and the step of generating challenge information and sending the challenge information to the cloud is performed;

[0020] If the digital signature value is different from the digital signature value in the homomorphically verifiable tag, it means that the data to be audited is incomplete and the audit is stopped.

[0021] Optionally, obtaining the certification information calculated by the cloud according to the challenge information, the file authentication code corresponding to the data to be audited, and the data to be audited includes:

[0022] The challenge information is sent to the cloud so that the cloud Calculate the first element of the proof information ,according to Calculate the second element of the proof information , and the certification information Sending to the audit end;

[0023] Receiving the certification information sent by the cloud;

[0024] in, Indicates challenge information. , Represents a random number, Indicates the index information of the data block. A random number representing the i-th data block; Represents the file authentication character. Indicates the number of random numbers in the challenge information; Represents an encrypted file divided into n blocks.

[0025] Optionally, before receiving the audit instruction of the data to be audited, the process further includes:

[0026] The file to be uploaded to the cloud is encrypted using a key of a symmetric encryption function to obtain an encrypted file, and the file label is obtained according to the encrypted file; the file includes the data to be audited;

[0027] Obtaining the file authentication code by using a hash function calculation according to the private key, the random number and the encrypted file;

[0028] Generate a component element using the random number, and generate a public key using the private key;

[0029] According to the public key, the component elements and the file label, the homomorphic verifiable label is calculated using a digital signature function;

[0030] The file authenticator, the encrypted file and the homomorphically verifiable tag are uploaded to the cloud.

[0031] Optionally, the file authentication code is obtained by using a hash function to calculate the file authentication code according to the private key, the random number and the encrypted file, including:

[0032] according to Calculate and obtain the file authentication character;

[0033] in, Represents the i-th file authentication character; represents a hash function; Represents a private key; Represents a random number, , represents a cyclic group with a large prime number q; represents an encrypted file divided into n blocks, ; n represents the number of blocks the encrypted file is divided into; s represents the number of sectors in each block.

[0034] Optionally, the homomorphic verifiable tag is calculated using a digital signature function according to the public key, the component elements and the file tag, including:

[0035] according to generating the homomorphically verifiable label;

[0036] in, ; ; ; ;

[0037] represents a homomorphically verifiable label; The elements that represent homomorphically verifiable labels are composed of Calculated composition; express The generator of represents a cyclic group with a large prime number q; Represents a public key; Indicates the file tag. () represents the digital signature function; Indicates the file name; Fs indicates the size of the file; n indicates the number of blocks the encrypted file is divided into; s indicates the number of sectors per block; Represents a public key; Represents a private key.

[0038] The present invention also provides a cloud data integrity audit device, comprising:

[0039] A challenge information generation module, for generating challenge information when receiving an audit instruction for the data to be audited, and sending the challenge information to a cloud; the cloud stores the data to be audited and the corresponding file authentication code;

[0040] A certification information acquisition module, used to obtain certification information calculated by the cloud based on the challenge information, the file authentication code corresponding to the data to be audited, and the data to be audited;

[0041] A data audit module is used to obtain the homomorphically verifiable tags corresponding to the data to be audited from the cloud, and determine whether the data to be audited is complete based on the proof information and the homomorphically verifiable tags.

[0042] The present invention also provides a cloud data integrity audit device, comprising:

[0043] Memory for storing computer programs;

[0044] A processor is used to implement the steps of the cloud data integrity audit method as described above when executing the computer program.

[0045] The present invention also provides a computer-readable storage medium, in which computer-executable instructions are stored. When the computer-executable instructions are loaded and executed by a processor, the steps of the cloud data integrity audit method as described above are implemented.

[0046] It can be seen that the present invention generates challenge information upon receiving an audit instruction for the data to be audited, and sends the challenge information to the cloud; the cloud stores the data to be audited and the corresponding file authenticator; obtains the proof information calculated by the cloud based on the challenge information, the file authenticator corresponding to the data to be audited, and the data to be audited; obtains the homomorphically verifiable tag corresponding to the data to be audited from the cloud, and determines whether the data to be audited is complete based on the proof information and the homomorphically verifiable tag. The present invention audits the integrity of cloud data based on an identity cryptography algorithm. The amount of data transmitted during the audit is independent of the size of the audited data, so high bandwidth costs are not required, reducing computing overhead.

[0047] In addition, the present invention also provides a cloud data integrity audit device, equipment and storage medium, which also have the above-mentioned beneficial effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0049] Figure 1 A flowchart of a cloud data integrity audit method provided by an embodiment of the present invention;

[0050] Figure 2 An example flow chart of a cloud data integrity audit method provided by an embodiment of the present invention;

[0051] Figure 3 A schematic diagram of the structure of a cloud data integrity audit device provided by an embodiment of the present invention;

[0052] Figure 4 A schematic diagram of the structure of a cloud data integrity audit device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0053] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings 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.

[0054] First, the meanings of several letters involved in this application are explained, and reference may be made to Table 1:

[0055] Table 1 Symbol description table

[0056]

[0057] With the rapid development of cloud computing technology, cloud computing has gained more and more popularity in the market. Cloud storage has the following advantages: scalable storage space, high availability, low cost, and flexible data access, making it effectively applicable to scenarios such as data archiving and backup. Both enterprises and individual users can migrate local data to the cloud and access the data in different locations and at different times. Cloud storage is gradually replacing traditional centralized file servers and document management systems, so cloud computing has huge market potential and application prospects.

[0058] When users interact with cloud data (cloud data), data integrity may be destroyed due to network failures, hacker attacks, etc. Cloud storage may also threaten data integrity due to natural disasters, administrators' misconduct, etc. In order to protect the integrity of cloud data, cloud data needs to be audited to detect data anomalies in a timely manner. When performing the audit process, the existing ones are generally implemented based on hash functions, in which TPA must first obtain all audited data, that is, all audited data needs to be downloaded from the cloud to the local, and then their hash values ​​are calculated and compared with the locally saved hash values ​​(the hash values ​​calculated before the data is uploaded to the cloud) before the judgment result can be given. It can be seen that this method will lead to high bandwidth costs and computing overhead. The existing technology also has a dynamic PDP (Provable data possession algorithm, which realizes data integrity audit function) method, which uses Merkle (a typical binary tree or multi-tree structure used to efficiently verify the integrity and security of data) hash tree to support data updates. This method still faces high data audit costs.

[0059] Therefore, how to provide a low-cost and efficient cloud data audit method is a technical problem that needs to be solved urgently. To this end, the present invention proposes a cloud data integrity audit method based on identity cryptography algorithm, in which the amount of data transmitted during the audit is independent of the size of the audited data. Figure 1 , Figure 1 A cloud data integrity audit method is provided in an embodiment of the present invention. The method may include:

[0060] S101: When an audit instruction of the data to be audited is received, challenge information is generated and sent to the cloud; the cloud stores the data to be audited and the corresponding file authenticator.

[0061] The executor of this embodiment is TPA. This embodiment does not limit TPA. For example, TPA can be a dedicated audit terminal, which receives audit instructions from the user terminal and audits the specified data in the cloud according to the audit instructions; or it can be a user terminal, that is, the user terminal directly audits the cloud data according to the audit requirements. When TPA receives the audit instruction, it can generate challenge information and send the challenge information to the cloud. It should be noted that the generation of challenge information in this embodiment has nothing to do with the audit data, and the challenge information can be generated based on random numbers. The specific process can refer to the following example: Select Different random numbers ,in i ∈ [ 1 , n ] , | | v i | | < | | q | | , Determined to be [ F s × r ] , the challenge information Recorded as .

[0062] It can be understood that in this embodiment, the cloud stores files with data to be audited, that is, the data to be audited is the data previously uploaded and stored in the cloud, and now the data stored in the cloud needs to be audited to verify whether the data has been tampered with and whether the data is complete. Furthermore, the cloud in this embodiment also stores the file authenticator and homomorphic verifiable tag corresponding to the data. The file authenticator and homomorphic verifiable tag are generated when the user previously uploaded the data to the cloud, and are uploaded and stored in the cloud together with the file. The data stored in the cloud can be audited later.

[0063] Specifically, the file uploading step is described, that is, before the audit instruction of the audited data is received, the following steps may also be included:

[0064] Step 11: Use the key of the symmetric encryption function to encrypt the file to be uploaded to the cloud to obtain the encrypted file, and obtain a file label based on the encrypted file; the file includes the data to be audited.

[0065] For the security of the file, the file needs to be encrypted when it is uploaded to the cloud. This embodiment does not limit the specific encryption method. This embodiment uses the key ssk of the symmetric encryption function Enc() to encrypt the file F. The encrypted file Expressed as in This embodiment does not limit the symmetric encryption function, for example, it may be an AES (Advanced Encryption Standard) algorithm, a DES (Data Encryption Standard) algorithm, etc.

[0066] In order to ensure the efficiency of data upload, the encrypted file Divide into n blocks, each block consists of s sectors. For convenience, encrypt files It can also be expressed as . Further get the file tag , File Tags Expressed as , Fs represents the file size.

[0067] Step 12: Based on the private key, random number and encrypted file, a hash function is used to calculate the file authentication code.

[0068] Specifically, select s random numbers and private key , and according to the random number , Private Key and encrypted files , using hash functions Calculate the file authenticator , the specific formula is as follows:

[0069] For each i, calculate each file authentication character , and further obtain the file authentication token , the file authenticator is a set, specifically represented by , where the hash function It is expressed as follows: .

[0070] Step 13: Generate the constituent elements using random numbers and generate the public key using the private key.

[0071] Specifically, according to the private key Calculate the public key , the specific formula is expressed as ,in . Using random numbers Generate the component element A. The specific formula is as follows:

[0072] For each i, calculate the constituent elements , the component element A is represented as .

[0073] Step 14: Based on the public key, constituent elements and file label, a homomorphic verifiable label is calculated using a digital signature function.

[0074] Specifically, according to the public key , component A and file label , and the unique file name of the file, use the digital signature function to calculate the digital signature value , by the digital signature value , file name, public key , component A and file label Together they form homomorphic verifiable tags , its formula expression is as follows:

[0075] .

[0076] Step 15: Upload the file authenticator, encrypted file, and homomorphically verifiable tag to the cloud.

[0077] Specifically, the file authentication , Encrypted Files and homomorphically verifiable labels Upload to the cloud, and further transfer the random number and private key Delete from local storage.

[0078] Furthermore, after receiving the audit instruction of the data to be audited, the following steps may be further included:

[0079] Step 21: Obtain the corresponding homomorphic verifiable tags from the cloud based on the data to be audited.

[0080] Specifically, after receiving the audit instruction of the data to be audited and before generating the challenge information, the corresponding homomorphic verifiable label can also be obtained from the cloud according to the file name of the data to be audited. .

[0081] Step 22: Based on the file name, constituent elements, public key and file tag in the homomorphically verifiable tag, a digital signature value is calculated using a digital signature function.

[0082] Specifically, according to the homomorphic verifiable label Get the file name name, component element A, public key K and file label , further using the digital signature function () Calculate the above-obtained data to obtain the digital signature value. The specific calculation formula is: .

[0083] Step 23: If the digital signature value is the same as the digital signature value in the homomorphically verifiable tag, the homomorphically verifiable tag is valid, and the steps of generating challenge information and sending the challenge information to the cloud are executed.

[0084] Step 24: If the digital signature value is different from the digital signature value in the homomorphically verifiable tag, it means that the data to be audited is incomplete and the audit is stopped.

[0085] Specifically, according to the calculated digital signature value and the homomorphic verifiable label The comparison result of the digital signature value in the cloud determines the homomorphic verifiable tag stored in the cloud Is it valid? When the homomorphic verifiable label Only when it is valid is it necessary to generate subsequent challenge information and proof information and perform integrity verification; if it is invalid, it means that the data to be audited is incomplete, and data destruction or tampering may have occurred in the cloud.

[0086] S102: Obtain certification information calculated by the cloud based on the challenge information, the file authentication identifier corresponding to the data to be audited, and the data to be audited.

[0087] When TPA sends the challenge information to the cloud, the cloud generates proof information using the audited data, file authenticator and challenge information pre-stored in the cloud, and sends it to TPA. Specifically, the specific process of computing the proof information in the cloud is as follows:

[0088] for , calculated And further obtain the first element of the proof information ,according to Calculate the second element of the proof information , the first element and the second element Joint component certification information .

[0089] S103: Obtain homomorphically verifiable tags corresponding to the data to be audited from the cloud, and determine whether the data to be audited is complete based on the proof information and the homomorphically verifiable tags.

[0090] Specifically, based on the homomorphic verifiable tag obtained from the cloud and the returned proof information Determine the integrity of the data to be audited. Specifically, the following steps may be included:

[0091] Step 31: Obtain the homomorphic verifiable tag corresponding to the audited data from the cloud;

[0092] Step 32: Obtain the component element A and the public key K from the homomorphically verifiable tag tag;

[0093] Step 33: Based on the component element A, public key K and proof information Check equation Is it correct?

[0094] Step 34: If correct, the audit data is complete;

[0095] Step 35: If incorrect, the data to be audited is incomplete.

[0096] Specifically, the corresponding homomorphic verifiable tag tag is obtained from the cloud according to the file name of the data to be audited, and the element A and public key K in the homomorphic verifiable tag tag, as well as the proof information, are obtained. calculate, Whether the equation is established, if it is established, it means that the equation is correct and the data to be audited is complete; otherwise, the equation is incorrect and the data to be audited is incomplete.

[0097] The cloud data integrity audit method provided by the embodiment of the present invention is applied. When receiving an audit instruction for the data to be audited, challenge information is generated and sent to the cloud; the data to be audited and the corresponding file authenticator are stored in the cloud; the cloud obtains the proof information calculated by the challenge information, the file authenticator corresponding to the data to be audited, and the data to be audited; the homomorphic verifiable tag corresponding to the data to be audited is obtained from the cloud, and whether the data to be audited is complete is determined based on the proof information and the homomorphic verifiable tag. This method audits the integrity of cloud data based on an identity cryptography algorithm. The amount of data transmitted during the audit is independent of the size of the audited data, so high bandwidth costs are not required, reducing computing overhead.

[0098] In order to make the present invention easier to understand, please refer to Figure 2 , Figure 2 The example flow chart of the cloud data integrity audit method provided by the embodiment of the present invention may specifically include:

[0099] Authenticators refers to a set of tools or systems used to verify user identities; Process Flow refers to the order and logical relationship of each step in a process; Data Flow refers to the process of moving data from the source to the destination in a system or network; Encrypt refers to the process of converting data into an unreadable form to protect its content from being accessed by unauthorized users, that is, the file encryption process; user refers to the user end; Cloud refers to the cloud; TPA refers to the audit end; challenge means initiating a challenge, that is, TPA sends the challenge information to the cloud; response means cloud feedback, that is, the cloud sends the proof information to TPA.

[0100] When the user has a large amount of file data to be uploaded to the cloud, in order to protect privacy, the user should use a symmetric encryption algorithm to encrypt the file and keep the key secret. Then, the encrypted file is cut into blocks, and each block is preset to the same size, and filled when it is insufficient. The user calculates the file tags and file authenticators of these file blocks, and digitally signs the file tags with digital signatures to obtain homomorphically verifiable tags, and then uploads the encrypted file, file authenticator and homomorphically verifiable tags to the cloud. When the user needs to access the file data, the user can directly challenge the cloud storage, or indirectly challenge the cloud storage through TPA. The cloud will then send the proof information calculated based on the challenge information and the corresponding homomorphically verifiable tag to the user or TPA, and then the user or TPA determines the integrity of the cloud data by verifying the proof information and the homomorphically verifiable tag. If the verification is successful, it means that the data is complete, otherwise the data is destroyed.

[0101] The cloud data integrity auditing device provided in an embodiment of the present invention is introduced below. The cloud data integrity auditing device described below and the cloud data integrity auditing method described above can be referenced to each other.

[0102] Please refer to Figure 3 , Figure 3 The schematic diagram of the structure of the cloud data integrity audit device provided by the embodiment of the present invention may include:

[0103] The challenge information generation module 100 is used to generate challenge information when receiving an audit instruction for the data to be audited, and send the challenge information to the cloud; the cloud stores the data to be audited and the corresponding file authentication code;

[0104] The certification information acquisition module 200 is used to obtain the certification information calculated by the cloud according to the challenge information, the file authentication code corresponding to the data to be audited, and the data to be audited;

[0105] The data audit module 300 is used to obtain the homomorphically verifiable tags corresponding to the data to be audited from the cloud, and determine whether the data to be audited is complete based on the proof information and the homomorphically verifiable tags.

[0106] Based on the above embodiment, the data audit module 300 may include:

[0107] A first acquisition unit, configured to acquire, from the cloud, a homomorphically verifiable tag corresponding to the data to be audited;

[0108] A second acquisition unit, configured to acquire a component element and a public key from the homomorphically verifiable tag;

[0109] A first verification unit is used to verify the equation according to the component elements, the public key and the certification information Is it correct? Among them, Indicates challenge information. , Represents a random number, Indicates the index information of the data block. represents the random number of the i-th data block, A represents the constituent elements, and Represents two elements of proof information; K represents the public key; represents the hash function; s represents the number of sectors per block; represents a generator;

[0110] A first verification result unit, used for verifying that if the result is correct, the data to be audited is complete;

[0111] The second verification result unit is used to verify that if it is incorrect, the data to be audited is incomplete.

[0112] Based on the above embodiment, the cloud data integrity audit device may further include:

[0113] An acquisition module, used for acquiring the corresponding homomorphic verifiable label from the cloud according to the data to be audited;

[0114] A digital signature calculation module, used to calculate a digital signature value using a digital signature function according to the file name, constituent elements, public key and file tag in the homomorphically verifiable tag;

[0115] A first verification result module, for executing the step of generating challenge information and sending the challenge information to the cloud if the digital signature value is the same as the digital signature value in the homomorphically verifiable tag, then the homomorphically verifiable tag is valid;

[0116] The second verification result module is used to indicate that the data to be audited is incomplete and the audit is stopped if the digital signature value is different from the digital signature value in the homomorphically verifiable tag.

[0117] Based on the above embodiment, the certification information acquisition module 200 may include:

[0118] A sending unit is used to send the challenge information to the cloud so that the cloud Calculate the first element of the proof information ,according to Calculate the second element of the proof information , and the certification information Sent to the audit end; wherein, Indicates challenge information. , Represents a random number, Indicates the index information of the data block. A random number representing the i-th data block; Represents the file authentication character. Indicates the number of random numbers in the challenge information; Represents an encrypted file divided into n blocks.

[0119] A receiving unit, configured to receive the certification information sent by the cloud;

[0120] Based on any of the above embodiments, the cloud data integrity audit device may further include:

[0121] An encryption module, used to encrypt the file to be uploaded to the cloud using a key of a symmetric encryption function to obtain an encrypted file, and obtain the file label according to the encrypted file; the file includes the data to be audited;

[0122] A file authentication code calculation module, used to calculate the file authentication code using a hash function according to a private key, a random number and the encrypted file;

[0123] A generation module, used to generate a component element using the random number and generate a public key using the private key;

[0124] A homomorphic verifiable label calculation module, used to calculate the homomorphic verifiable label using a digital signature function according to the public key, the component elements and the file label;

[0125] An uploading module is used to upload the file authenticator, the encrypted file and the homomorphically verifiable tag to the cloud.

[0126] Based on the above embodiment, the file authentication code calculation module may include:

[0127] The file authentication code calculation unit is used to calculate the file authentication code according to the The file authentication code is obtained by calculation; wherein, Represents the i-th file authentication character; represents a hash function; Represents a private key; Represents a random number, , represents a cyclic group with a large prime number q; represents an encrypted file divided into n blocks, ; n represents the number of blocks the encrypted file is divided into; s represents the number of sectors in each block.

[0128] Based on the above embodiment, the homomorphic verifiable tag calculation module may include:

[0129] Homomorphic verifiable label computation unit, used to Generate the homomorphic verifiable label; wherein, ; ; ; ; represents a homomorphically verifiable label; The elements that represent homomorphically verifiable labels are composed of Calculated composition; express The generator of represents a cyclic group with a large prime number q; Represents a public key; Indicates the file tag. () represents the digital signature function; Indicates the file name; Fs indicates the size of the file; n indicates the number of blocks the encrypted file is divided into; s indicates the number of sectors per block; Represents a public key; Represents a private key.

[0130] It should be noted that the order of the modules and units in the above-mentioned cloud data integrity audit device can be changed without affecting the logic.

[0131] The cloud data integrity audit device provided by the embodiment of the present invention is used to generate challenge information when receiving an audit instruction for the data to be audited, and send the challenge information to the cloud; the cloud stores the data to be audited and the corresponding file authenticator; the proof information acquisition module 200 is used to obtain the proof information calculated by the cloud based on the challenge information, the file authenticator corresponding to the data to be audited, and the data to be audited; the data audit module 300 is used to obtain the homomorphic verifiable label corresponding to the data to be audited from the cloud, and determine whether the data to be audited is complete based on the proof information and the homomorphic verifiable label. This device audits the integrity of cloud data based on the identity cryptography algorithm. The amount of data transmitted during the audit is independent of the scale of the audited data, so high bandwidth costs are not required, reducing computing overhead.

[0132] The cloud data integrity audit device provided in an embodiment of the present invention is introduced below. The cloud data integrity audit device described below and the cloud data integrity audit method described above can be referenced to each other.

[0133] Please refer to Figure 4 , Figure 4 A schematic diagram of the structure of a cloud data integrity audit device provided by an embodiment of the present invention may include:

[0134] A memory 10, used for storing computer programs;

[0135] The processor 20 is used to execute a computer program to implement the above-mentioned cloud data integrity audit method.

[0136] The memory 10 , the processor 20 , and the communication interface 31 all communicate with each other via the communication bus 32 .

[0137] In the embodiment of the present invention, the memory 10 is used to store one or more programs, and the program may include program code, and the program code includes computer operation instructions. In the embodiment of the present invention, the memory 10 may store programs for implementing the following functions:

[0138] When receiving an audit instruction for the data to be audited, a challenge message is generated and sent to the cloud; the cloud stores the data to be audited and the corresponding file authentication token;

[0139] Obtain the certification information calculated by the cloud based on the challenge information, the file authentication symbol corresponding to the data to be audited, and the data to be audited;

[0140] Obtain the homomorphically verifiable tags corresponding to the data to be audited from the cloud, and determine whether the data to be audited is complete based on the proof information and the homomorphically verifiable tags.

[0141] In a possible implementation, the memory 10 may include a program storage area and a data storage area, wherein the program storage area may store an operating system and an application required for at least one function, etc.; the data storage area may store data created during use.

[0142] In addition, the memory 10 may include a read-only memory and a random access memory, and provide instructions and data to the processor. A portion of the memory may also include an NVRAM. The memory stores an operating system and operating instructions, executable modules or data structures, or a subset thereof, or an extended set thereof, wherein the operating instructions may include various operating instructions for implementing various operations. The operating system may include various system programs for implementing various basic tasks and processing hardware-based tasks.

[0143] The processor 20 may be a central processing unit (CPU), an application specific integrated circuit, a digital signal processor, a field programmable gate array or other programmable logic device, a microprocessor or any conventional processor, etc. The processor 20 may call a program stored in the memory 10 .

[0144] The communication interface 31 may be an interface of a communication module, and is used to connect to other devices or systems.

[0145] Of course, it should be noted that Figure 4 The structure shown does not constitute a limitation on the cloud data integrity audit device in the embodiment of the present invention. In actual applications, the cloud data integrity audit device may include Figure 4 More or fewer components than shown, or combinations of certain components.

[0146] The following is an introduction to the computer-readable storage medium provided in an embodiment of the present invention. The computer-readable storage medium described below and the cloud data integrity audit method described above can be referenced to each other.

[0147] The present invention also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the above-mentioned cloud data integrity audit method are implemented.

[0148] The computer-readable storage medium may include: a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and other media that can store program codes.

[0149] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0150] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in the above description according to function. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0151] Finally, it should be noted that, in this article, relationships such as first and second, etc. are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprises" or any other variations are intended to cover non-exclusive inclusion, so that a process, method, article or device that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0152] The cloud data integrity audit method, device, equipment and storage medium provided by the present invention are introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea; at the same time, for general technical personnel in this field, according to the idea of ​​the present invention, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A cloud data integrity audit method, characterized in that: include: When receiving an audit instruction for the data to be audited, generating challenge information, and sending the challenge information to the cloud; The cloud stores the data to be audited and the corresponding file authentication code; Obtaining certification information calculated by the cloud based on the challenge information, the file authentication code corresponding to the data to be audited, and the data to be audited; Obtain a homomorphically verifiable tag corresponding to the data to be audited from the cloud, and determine whether the data to be audited is complete based on the proof information and the homomorphically verifiable tag.

2. The cloud data integrity audit method according to claim 1, characterized in that: Obtaining a homomorphically verifiable tag corresponding to the data to be audited from the cloud, and determining whether the data to be audited is complete according to the certification information and the homomorphically verifiable tag, including: Obtaining a homomorphically verifiable tag corresponding to the data to be audited from the cloud; Obtaining constituent elements and a public key from the homomorphically verifiable tag; Verify the equation based on the component elements, the public key and the certification information Is it correct? Among them, Indicates challenge information. , Represents a random number, Indicates the index information of the data block. represents the random number of the i-th data block, A represents the constituent elements, and Represents two elements of proof information; K represents the public key; represents the hash function; s represents the number of sectors per block; represents a generator; If correct, the data to be audited is complete; If it is incorrect, the data to be audited is incomplete.

3. The cloud data integrity audit method according to claim 1, characterized in that: After receiving the audit instruction of the data to be audited, it also includes: Acquire the corresponding homomorphic verifiable tag from the cloud according to the data to be audited; A digital signature value is calculated using a digital signature function according to the file name, constituent elements, public key and file tag in the homomorphically verifiable tag; If the digital signature value is the same as the digital signature value in the homomorphically verifiable tag, the homomorphically verifiable tag is valid, and the step of generating challenge information and sending the challenge information to the cloud is performed; If the digital signature value is different from the digital signature value in the homomorphically verifiable tag, it means that the data to be audited is incomplete and the audit is stopped.

4. The cloud data integrity audit method according to claim 1, characterized in that: Obtaining the certification information calculated by the cloud according to the challenge information, the file authentication code corresponding to the data to be audited, and the data to be audited, including: The challenge information is sent to the cloud so that the cloud Calculate the first element of the proof information ,according to Calculate the second element of the proof information , and the certification information Sending to the audit end; Receiving the certification information sent by the cloud; in, Indicates challenge information. , Represents a random number, Indicates the index information of the data block. A random number representing the i-th data block; Represents the file authentication character. Indicates the number of random numbers in the challenge information; Represents an encrypted file divided into n blocks.

5. The metadata integrity audit method according to any one of claims 1 to 4, characterized in that: Before receiving the audit instruction of the data to be audited, it also includes: The file to be uploaded to the cloud is encrypted using a key of a symmetric encryption function to obtain an encrypted file, and the file label is obtained according to the encrypted file; the file includes the data to be audited; The file authentication code is calculated using a hash function based on the private key, random number and the encrypted file. Generate a component element using the random number, and generate a public key using the private key; According to the public key, the component elements and the file label, the homomorphic verifiable label is calculated using a digital signature function; The file authenticator, the encrypted file and the homomorphically verifiable tag are uploaded to the cloud.

6. The cloud data integrity audit method according to claim 5, characterized in that: The file authentication code is obtained by using a hash function according to the private key, the random number and the encrypted file, including: according to Calculate and obtain the file authentication character; in, Represents the i-th file authentication character; represents a hash function; Represents a private key; Represents a random number, , represents a cyclic group with a large prime number q; represents an encrypted file divided into n blocks, ; n represents the number of blocks the encrypted file is divided into; s represents the number of sectors in each block.

7. The cloud data integrity audit method according to claim 5, characterized in that: The homomorphic verifiable tag is calculated using a digital signature function according to the public key, the constituent elements and the file tag, including: according to generating the homomorphically verifiable label; in, ; ; ; ; represents a homomorphically verifiable label; The elements that represent homomorphically verifiable labels are composed of Calculated composition; express The generator of represents a cyclic group with a large prime number q; Represents a public key; Indicates the file tag. () represents the digital signature function; Indicates the file name; Fs indicates the size of the file; n indicates the number of blocks the encrypted file is divided into; s indicates the number of sectors per block; Represents a public key; Represents a private key.

8. A cloud data integrity audit device, characterized in that: include: A challenge information generation module, configured to generate challenge information when receiving an audit instruction for the data to be audited, and send the challenge information to the cloud; The cloud stores the data to be audited and the corresponding file authentication code; A certification information acquisition module, used to obtain certification information calculated by the cloud based on the challenge information, the file authentication code corresponding to the data to be audited, and the data to be audited; A data audit module is used to obtain the homomorphically verifiable tags corresponding to the data to be audited from the cloud, and determine whether the data to be audited is complete based on the proof information and the homomorphically verifiable tags.

9. A cloud data integrity audit device, characterized in that: include: Memory for storing computer programs; A processor, configured to implement the steps of the cloud data integrity audit method as described in any one of claims 1 to 7 when executing the computer program.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer-executable instructions, and when the computer-executable instructions are loaded and executed by the processor, the steps of the cloud data integrity audit method according to any one of claims 1 to 7 are implemented.

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