A data deletion method, device, apparatus, and storage medium

Abstract

The embodiment of the application provides a data deletion method, device and equipment and a storage medium. The method first encrypts data and divides the data into blocks, converts the data ciphertext after the division into a binary form, and performs an inversion process, so that the public cloud does not store the real data ciphertext, and the ciphertext key is stored in the private cloud by using a shamir key sharing algorithm, self-key management is realized, a third-party auditing agency is not used, and the risk of data leakage is reduced. When a user wants to delete data, the user only needs to delete the key ciphertext corresponding to the data ciphertext in the main storage node. The application uses the key ciphertext deletion and the special data ciphertext processing mode to realize trusted deletion of cloud data, especially for a hybrid cloud architecture, security access of user data is guaranteed, and the security of data storage is improved.

Description

Technical Field

[0001] This application relates to the field of cloud storage technology, and in particular to a method, apparatus, device and storage medium for deleting data. Background Technology

[0002] Currently, with the increasing development of cloud computing technology, cloud storage services have been widely used.

[0003] As a crucial user asset, data storage security is naturally a key focus in cloud computing. To improve the reliability of cloud services, cloud service providers (CSPs) typically create multiple backups of data. However, when users delete data, CSPs may not completely delete all data and backups, posing a possibility of active or passive leakage of user data.

[0004] For sensitive data, traditional methods often require local users to permanently delete it through repeated rewrite operations or even physical destruction. However, in cloud storage systems, users lose physical control over their data, making it impossible to guarantee that cloud service providers will securely delete their data according to their wishes. Summary of the Invention

[0005] This application provides a data deletion method, apparatus, device, and storage medium to achieve reliable deletion of cloud data and reduce the risk of data leakage.

[0006] In a first aspect, embodiments of this application provide a data deletion method, applied to a user terminal, including:

[0007] Data is encrypted using a symmetric encryption algorithm to obtain ciphertext, and the key used to encrypt the data is encrypted using an asymmetric encryption algorithm to obtain key ciphertext.

[0008] The encrypted data is converted into binary form and inverted. The inverted encrypted data is then processed into blocks and stored in a public cloud. The encrypted key is processed into blocks and then distributed and stored in a private cloud using the Shamir key sharing algorithm.

[0009] In response to a user's deletion operation, a deletion request is sent to both the private cloud and the public cloud, so that the private cloud randomly deletes a first preset number of key ciphertext blocks in the main storage node of key management, and the public cloud deletes the data ciphertext.

[0010] In some embodiments, storing the inverted encrypted data in blocks to a public cloud includes:

[0011] The inverted ciphertext is divided into N equal parts to obtain N ciphertext blocks, where N is a positive integer greater than 2;

[0012] For any given data ciphertext block, determine the homomorphic hash value of the data ciphertext block based on the homomorphic hashing rule;

[0013] An H-MHT tree is constructed based on the homomorphic hash value of the encrypted data block and the preset initial weight of the encrypted data block. A signature is obtained by binding the root node of the H-MHT tree with a private key. The signature and the encrypted data block are then stored in a public cloud.

[0014] In some embodiments, determining the homomorphic hash value of the data ciphertext block based on homomorphic hashing rules includes:

[0015] The encrypted data block is divided into M basic storage blocks based on the homomorphic hashing rule, where M is a positive integer less than N;

[0016] The sum of the numerical values ​​of the M basic storage blocks is used as the homomorphic hash value of the data ciphertext block.

[0017] Secondly, embodiments of this application also provide a data deletion method, applied to a private cloud, including:

[0018] After receiving the ciphertext of the block processing key sent by the user, the ciphertext of the block processing key is distributed and stored using the Shamir key sharing algorithm;

[0019] Upon receiving a deletion request from the user terminal, a first preset number of key ciphertext blocks are randomly deleted from the main storage node of key management;

[0020] After verifying the integrity of the key ciphertext in the main storage node, if less than the second preset number of key ciphertext blocks are obtained or no key ciphertext blocks are obtained, a message indicating successful deletion is sent to the user terminal.

[0021] In some embodiments, after sending a successful deletion message to the user terminal, the method further includes:

[0022] The Redis Sentinel mechanism is used to verify the root value of the corresponding H-MHT tree in each slave storage node. If the root value is different from the root value of the corresponding H-MHT tree in the master storage node, data synchronization is performed on the slave node.

[0023] In some embodiments, after verifying the integrity of the key ciphertext in the primary storage node, the method further includes:

[0024] If a key ciphertext block greater than or equal to the second preset number is obtained, a deletion failure message is sent to the user terminal.

[0025] Use the Redis Sentinel mechanism to switch between master and slave storage nodes;

[0026] Randomly delete a first preset number of key ciphertext blocks from the switched primary storage node;

[0027] After verifying the integrity of the key ciphertext in the switched primary storage node, if less than the second preset number of key ciphertext blocks are obtained or no key ciphertext blocks are obtained, a message indicating successful deletion is sent to the user terminal.

[0028] Thirdly, embodiments of this application also provide a data deletion device, comprising:

[0029] The encryption unit is used to encrypt data based on a symmetric encryption algorithm to obtain data ciphertext, and to encrypt the key used to encrypt the data based on an asymmetric encryption algorithm to obtain key ciphertext.

[0030] The processing unit is used to convert the data ciphertext into binary form and perform inversion processing, process the inverted data ciphertext into blocks and store it in the public cloud, and process the key ciphertext into blocks and distribute it in the private cloud using the Shamir key sharing algorithm.

[0031] The request unit is used to respond to the user's deletion operation and send deletion requests to both the private cloud and the public cloud, so that the private cloud randomly deletes a first preset number of key ciphertext blocks in the main storage node of key management, and the public cloud deletes the data ciphertext.

[0032] In some embodiments, the processing unit is specifically used for:

[0033] The inverted ciphertext is divided into N equal parts to obtain N ciphertext blocks, where N is a positive integer greater than 2;

[0034] For any given data ciphertext block, determine the homomorphic hash value of the data ciphertext block based on the homomorphic hashing rule;

[0035] An H-MHT tree is constructed based on the homomorphic hash value of the encrypted data block and the preset initial weight of the encrypted data block. A signature is obtained by binding the root node of the H-MHT tree with a private key. The signature and the encrypted data block are then stored in a public cloud.

[0036] In some embodiments, the processing unit is specifically used for:

[0037] The encrypted data block is divided into M basic storage blocks based on the homomorphic hashing rule, where M is a positive integer less than N;

[0038] The sum of the numerical values ​​of the M basic storage blocks is used as the homomorphic hash value of the data ciphertext block.

[0039] Fourthly, embodiments of this application also provide a data deletion device, comprising:

[0040] The storage unit is used to distribute the ciphertext of the block processing key sent by the user terminal in a distributed manner using the Shamir key sharing algorithm after receiving the ciphertext of the block processing key.

[0041] The deletion unit is used to randomly delete a first preset number of key ciphertext blocks in the main storage node of key management after receiving a deletion request sent by the user terminal.

[0042] The verification unit is used to verify the integrity of the key ciphertext in the main storage node. If less than a second preset number of key ciphertext blocks are obtained or no key ciphertext blocks are obtained, a deletion success message is sent back to the user terminal.

[0043] In some embodiments, the verification unit is specifically used for:

[0044] The Redis Sentinel mechanism is used to verify the root value of the corresponding H-MHT tree in each slave storage node. If the root value is different from the root value of the corresponding H-MHT tree in the master storage node, data synchronization is performed on the slave node.

[0045] In some embodiments, the verification unit is specifically used for:

[0046] If a key ciphertext block greater than or equal to the second preset number is obtained, a deletion failure message is sent to the user terminal.

[0047] Use the Redis Sentinel mechanism to switch between master and slave storage nodes;

[0048] Randomly delete a first preset number of key ciphertext blocks from the switched primary storage node;

[0049] After verifying the integrity of the key ciphertext in the switched primary storage node, if less than the second preset number of key ciphertext blocks are obtained or no key ciphertext blocks are obtained, a message indicating successful deletion is sent to the user terminal.

[0050] Fifthly, embodiments of this application also provide an electronic device, including a memory and a processor;

[0051] The memory is used to store instructions;

[0052] The processor is configured to execute instructions stored in the memory, and when the processor executes the instructions stored in the memory, it causes the electronic device to perform the method as described in either the first aspect or the second aspect.

[0053] Sixthly, embodiments of this application also provide a computer storage medium storing instructions that, when executed on a computer, cause the computer to perform the method described in either the first or second aspect.

[0054] This application provides a data deletion method, apparatus, device, and storage medium. The method encrypts data using a symmetric encryption algorithm to obtain ciphertext, and encrypts the key used to encrypt the data using an asymmetric encryption algorithm to obtain key ciphertext. The ciphertext is converted to binary form and inverted. The inverted ciphertext is then processed into blocks and stored in a public cloud. The key ciphertext is also processed into blocks and distributed in a private cloud using the Shamir key-sharing algorithm. In response to a user's deletion operation, a deletion request is sent to both the private cloud and the public cloud. This causes the private cloud to randomly delete a first preset number of key ciphertext blocks from the main storage node for key management, and the public cloud to delete the ciphertext.

[0055] The data deletion method provided in this application first encrypts and divides the data into blocks. The encrypted data blocks are then converted to binary form and inverted, ensuring that the public cloud does not store the actual encrypted data. The encrypted keys are distributed and stored in a private cloud using the Shamir key-sharing algorithm, enabling self-management of keys and eliminating the need for third-party auditing, thus reducing the risk of data leakage. When a user wants to delete data, they only need to delete the encrypted key corresponding to the encrypted data in the main storage node. This application achieves trusted deletion of cloud data through key-encrypted deletion and special data encryption processing, particularly for hybrid cloud architectures, ensuring secure access to user data and improving data storage security. Attached Figure Description

[0056] To more clearly illustrate the technical solutions of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0057] Figure 1 A flowchart illustrating a data deletion method provided in an embodiment of this application;

[0058] Figure 2 A flowchart illustrating another data deletion method provided in an embodiment of this application;

[0059] Figure 3 This is a schematic diagram of the structure of a data deletion device provided in an embodiment of this application;

[0060] Figure 4A schematic diagram of another data deletion device provided in an embodiment of this application;

[0061] Figure 5 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0062] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art are within the scope of protection of this application.

[0063] With the development of cloud storage services, ensuring the reliable deletion of cloud data is crucial for protecting user privacy. Currently, the mainstream methods for secure data deletion in the cloud involve using trusted third-party organizations to manage and delete keys, or relying on data re-encryption and overwriting. However, introducing third-party organizations carries the risk of key leakage and is not always reliable; deleting keys indirectly ensures data security but does not achieve true data deletion, as the data still exists in the cloud; re-encryption and overwriting methods suffer from low deletion efficiency and long waiting times for users.

[0064] To address the issue of secure deletion of user data in cloud storage and improve data security in the cloud environment, this application provides a cloud data trusted deletion method with multiple protection mechanisms in a hybrid cloud storage environment. This method improves the security of stored data in the increasingly widely used hybrid cloud storage architecture, solves the aforementioned problems, and simultaneously increases the utilization rate of hybrid cloud resources, fully leveraging the technical advantages of the hybrid cloud architecture.

[0065] like Figure 1 The illustration shows a data deletion method provided in this application, applied to a user terminal. The method includes:

[0066] S101. Encrypt the data using a symmetric encryption algorithm to obtain the data ciphertext, and encrypt the key used to encrypt the data using an asymmetric encryption algorithm to obtain the key ciphertext.

[0067] S102. Convert the encrypted data into binary form and invert it. Then, process the inverted encrypted data into blocks and store it in the public cloud. Process the key encrypted data into blocks and distribute it in the private cloud using the Shamir key sharing algorithm.

[0068] S103. In response to the user's deletion operation, send deletion requests to both the private cloud and the public cloud, so that the private cloud randomly deletes a first preset number of key ciphertext blocks in the main storage node of key management, and the public cloud deletes the data ciphertext.

[0069] The data deletion method provided in this application first encrypts and divides the data into blocks. The encrypted data blocks are then converted to binary form and inverted, ensuring that the public cloud does not store the actual encrypted data. The encrypted keys are distributed and stored in a private cloud using the Shamir key-sharing algorithm, enabling self-management of keys and eliminating the need for third-party auditing, thus reducing the risk of data leakage. When a user wants to delete data, they only need to delete the encrypted key corresponding to the encrypted data in the main storage node. This application achieves trusted deletion of cloud data through key-encrypted deletion and special data encryption processing, particularly for hybrid cloud architectures, ensuring secure access to user data and improving data storage security.

[0070] In practice, for users who possess data, the system will generate a signature for them. public and private key pairs Simultaneously generate homomorphic hash keys The client encrypts the data using a symmetric encryption algorithm to obtain ciphertext, and then encrypts the key used to encrypt the data using an asymmetric encryption algorithm to obtain key ciphertext. The key ciphertext is then divided into N equal parts and distributed and stored in a private cloud using the Shamir key-sharing algorithm.

[0071] The above encryption process uses CP-ABE attribute encryption. The specific encryption and access process is as follows:

[0072] ① Randomly generate a user-unique key and a file key to generate public parameters PK and master key MK for the CP-ABE algorithm; ② Preprocess the original file data with AES encryption, upload the ciphertext and file key together to the private cloud, encrypt the key information with CP-ABE attributes, and then use the Shamir secret sharing algorithm to enhance the storage security of the user key information; ③ The user authenticates the system using their personal account and password, and the private cloud generates the private key and access permissions for the CP-ABE asymmetric encryption algorithm based on the user attribute set; ④ The public cloud sends the ciphertext of the file to the private cloud according to the access request, and then uses the recovery technology corresponding to the sharing algorithm to deduce the ciphertext of the key. At this time, the ciphertext of the file, the ciphertext of the key, and the CP-ABE private key are all sent to the user. The user decrypts the file key using the CP-ABE private key and can then obtain the desired file data; ⑤ This part adds the public and private keys of the shared party to the download and decryption process. This element makes the sharing process proactive and unique.

[0073] In practice, the user terminal converts the encrypted data into binary form and inverts it. The inverted encrypted data is then divided into blocks and stored in the public cloud. Specifically, the encrypted data is divided into N equal parts, resulting in N encrypted data blocks, where N is a positive integer greater than 2. For any given encrypted data block, it is divided into M basic storage blocks based on homomorphic hashing rules, where M is a positive integer less than N. The sum of the values ​​of the M basic storage blocks is used as the homomorphic hash value of the encrypted data block. An H-MHT tree is constructed based on the homomorphic hash value and the preset initial weights of the encrypted data blocks. A signature is obtained by binding the root node of the H-MHT tree with a private key. The signature and the encrypted data blocks are then stored in the public cloud.

[0074] For example, the client first converts the encrypted data into binary form and inverts it, then divides the processed binary encrypted data into blocks. Then, based on the homomorphic hash rule, each part of the data is further divided into m basic storage blocks. ,in ; Calculate the tag value of each encrypted data block Homomorphic hash value Randomly assign initial weights to each data ciphertext block. , combined and Construct an H-MHT tree using a private key For the root node of the tree sign All information generated Uploaded to the public cloud. Among them, .

[0075] Based on the same concept, embodiments of this application also provide a method for deleting data, such as... Figure 2 As shown, applied to a private cloud, the method includes:

[0076] S201. After receiving the ciphertext of the block processing key sent by the user terminal, the ciphertext of the block processing key is distributed and stored using the Shamir key sharing algorithm.

[0077] S202. After receiving the deletion request sent by the user, randomly delete a first preset number of key ciphertext blocks in the main storage node of key management;

[0078] S203. After verifying the integrity of the key ciphertext in the main storage node, if less than the second preset number of key ciphertext blocks are obtained or no key ciphertext blocks are obtained, a message indicating successful deletion is sent to the user.

[0079] The data deletion method provided in this application embodiment, after receiving the ciphertext of the block processing key sent by the user terminal, uses the Shamir key sharing algorithm to distribute and store the ciphertext of the block processing key, which can realize independent key management, does not require a third-party auditing agency, and reduces the risk of data leakage. When the user wants to delete data, he only needs to delete the ciphertext of the key corresponding to the data ciphertext in the main storage node. Furthermore, the integrity verification of the ciphertext of the key in the main storage node is also performed, which can improve the verification efficiency.

[0080] In practice, after receiving a deletion request from the user, if the request is valid, the private cloud can randomly and securely remove at least N-M+1 key ciphertext blocks from the main storage node of key management to ensure that the complete key information cannot be recovered (where N is the total number of key ciphertext blocks and M is the minimum number of blocks required to recover the information). Then, the integrity of the key ciphertext information in the main storage node is verified. If multiple verifications fail to obtain M key ciphertext blocks to recover the complete key ciphertext information, the deletion operation in the main storage node is considered successful, and a new root value of the H-MHT verification tree is generated.

[0081] The specific process of the above integrity verification is as follows:

[0082] ① The user terminal randomly generates the key parameter e and determines the number of data blocks c to be challenged, and then sends the integrity verification challenge information to the private cloud. ;

[0083] ② Private cloud received Then, based on the random parameter e, the data block that needs to be challenged in block c is found. At this point, the corresponding data block label and the homomorphic hash value of the underlying actual stored data can be obtained. Where 1≤i≤c, 1≤t≤m. This is further combined with the H-MHT tree... Auxiliary authentication information tuple The following evidence can be generated: , , ;

[0084] ③ The user receives the evidence generated by the private cloud and first, based on... Calculate the content of the root node Then by the user's public key Verify that the currently calculated content matches the signature uploaded to the public cloud. Are they equal? ​​If and only if the above root nodes are equal. Only after successful verification will the data block content verification proceed. First, the data blocks are calculated to obtain the data block size used to generate each tag in the previous data tagging operation. Then, using the hash homomorphic calculation rule, the hash values ​​of the detection data are obtained based on the actual content and the tag data respectively.

[0085]

[0086] Finally, determine whether the two calculated values ​​are equal. If they are equal, it means that the data can be recovered normally, and the data deletion fails; otherwise, the data cannot be recovered, and the deletion is successful.

[0087] In practice, after sending a successful deletion message to the user, the process may also include: using the Redis Sentinel mechanism to verify the root value of the corresponding H-MHT tree in each slave storage node; if it is different from the root value of the corresponding H-MHT tree in the master storage node, then performing data synchronization processing such as re-bringing the slave node back online.

[0088] In practical implementation, after verifying the integrity of the key ciphertext in the primary storage node, the process may further include: if a key ciphertext block greater than or equal to a second preset number is obtained, a deletion failure message is sent to the user; a master-slave storage node switch is performed using the Redis Sentinel mechanism; a first preset number of key ciphertext blocks are randomly deleted from the switched primary storage node; after verifying the integrity of the key ciphertext in the switched primary storage node, if a key ciphertext block less than the second preset number is obtained or no key ciphertext block is obtained, a deletion success message is sent to the user. In other words, if the secure removal of key ciphertext blocks from the primary storage node fails, the process is repeated after a master-slave storage node switch using the Sentinel mechanism.

[0089] Based on the same concept, embodiments of this application also provide a data deletion device. The implementation of this device can refer to the implementation of the above-described method; repeated details will not be elaborated further. Figure 3 As shown, the data deletion device includes:

[0090] The encryption unit 301 is used to encrypt data based on a symmetric encryption algorithm to obtain data ciphertext, and to encrypt the key used to encrypt the data based on an asymmetric encryption algorithm to obtain key ciphertext.

[0091] The processing unit 302 is used to convert the data ciphertext into binary form and perform inversion processing, process the inverted data ciphertext into blocks and store it in the public cloud, and process the key ciphertext into blocks and distribute it in the private cloud using the Shamir key sharing algorithm.

[0092] The request unit 303 is used to respond to the user's deletion operation and send deletion requests to both the private cloud and the public cloud, so that the private cloud randomly deletes a first preset number of key ciphertext blocks in the main storage node of key management, and the public cloud deletes the data ciphertext.

[0093] In some embodiments, the processing unit 302 is specifically used for:

[0094] The inverted ciphertext is divided into N equal parts to obtain N ciphertext blocks, where N is a positive integer greater than 2;

[0095] For any given data ciphertext block, determine the homomorphic hash value of the data ciphertext block based on the homomorphic hashing rule;

[0096] An H-MHT tree is constructed based on the homomorphic hash value and the preset initial weight of the data ciphertext block. A signature is obtained by binding the root node of the H-MHT tree with a private key. The signature and the data ciphertext block are then stored in the public cloud.

[0097] In some embodiments, the processing unit 302 is specifically used for:

[0098] Based on the homomorphic hashing rule, the encrypted data block is divided into M basic storage blocks, where M is a positive integer less than N;

[0099] The sum of the numerical values ​​of the M basic storage blocks is used as the homomorphic hash value of the data ciphertext block.

[0100] Based on the same concept, embodiments of this application also provide a data deletion device. The implementation of this device can refer to the implementation of the above-described method; repeated details will not be elaborated further. Figure 4 As shown, the data deletion device includes:

[0101] Storage unit 401 is used to receive the ciphertext of the block processing key sent by the user terminal and then distribute and store the ciphertext of the block processing key using the Shamir key sharing algorithm.

[0102] The deletion unit 402 is used to randomly delete a first preset number of key ciphertext blocks in the main storage node of key management after receiving a deletion request sent by the user terminal.

[0103] The verification unit 403 is used to verify the integrity of the key ciphertext in the main storage node. If less than the second preset number of key ciphertext blocks are obtained or no key ciphertext blocks are obtained, a message indicating successful deletion is sent to the user terminal.

[0104] In some embodiments, the verification unit 403 is specifically used for:

[0105] The Redis Sentinel mechanism is used to verify the root value of the corresponding H-MHT tree in each slave storage node. If the root value is different from the root value of the corresponding H-MHT tree in the master storage node, data synchronization is performed on the slave node.

[0106] In some embodiments, the verification unit 403 is specifically used for:

[0107] If a key ciphertext block greater than or equal to the second preset number is obtained, a deletion failure message is sent to the user.

[0108] Use the Redis Sentinel mechanism to switch between master and slave storage nodes;

[0109] Randomly delete a first preset number of key ciphertext blocks from the switched primary storage node;

[0110] After verifying the integrity of the key ciphertext in the switched primary storage node, if less than the second preset number of key ciphertext blocks are obtained or no key ciphertext blocks are obtained, a message indicating successful deletion is sent to the user.

[0111] Based on the same inventive concept, this application also provides an electronic device, the implementation of which can refer to the implementation of the above-described method, and the repeated parts will not be described again. Figure 5 As shown, the electronic device includes a memory 501 and a processor 502;

[0112] Memory 501 is used to store instructions;

[0113] The processor 502 is configured to execute instructions stored in the memory 501, and when the processor 502 executes the instructions stored in the memory, the device performs the data deletion method described in any of the preceding claims.

[0114] Furthermore, embodiments of the present invention also provide a computer storage medium storing instructions that, when executed on a computer, cause the computer to perform the data deletion method described in any of the preceding claims.

[0115] This application provides a data deletion method, apparatus, device, and storage medium. The method encrypts data using a symmetric encryption algorithm to obtain ciphertext, and encrypts the key used to encrypt the data using an asymmetric encryption algorithm to obtain key ciphertext. The ciphertext is converted to binary form and inverted. The inverted ciphertext is then processed into blocks and stored in a public cloud. The key ciphertext is also processed into blocks and distributed in a private cloud using the Shamir key-sharing algorithm. In response to a user's deletion operation, a deletion request is sent to both the private cloud and the public cloud. This causes the private cloud to randomly delete a first preset number of key ciphertext blocks from the main storage node for key management, and the public cloud to delete the ciphertext.

[0116] The data deletion method provided in this application first encrypts and divides the data into blocks. The encrypted data blocks are then converted to binary form and inverted, ensuring that the public cloud does not store the actual encrypted data. The encrypted keys are distributed and stored in a private cloud using the Shamir key-sharing algorithm, enabling self-management of keys and eliminating the need for third-party auditing, thus reducing the risk of data leakage. When a user wants to delete data, they only need to delete the encrypted key corresponding to the encrypted data in the main storage node. This application achieves trusted deletion of cloud data through key-encrypted deletion and special data encryption processing, particularly for hybrid cloud architectures, ensuring secure access to user data and improving data storage security.

[0117] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0118] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to this application. It should be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0119] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0120] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0121] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A method for deleting data, characterized in that, Applied to the user end, including: Data is encrypted using a symmetric encryption algorithm to obtain ciphertext, and the key used to encrypt the data is encrypted using an asymmetric encryption algorithm to obtain key ciphertext. The encrypted data is converted to binary form and inverted. The inverted encrypted data is then divided into N equal parts to obtain N encrypted data blocks. For any encrypted data block, a homomorphic hash value is determined based on a homomorphic hashing rule. An H-MHT tree is constructed based on the homomorphic hash value and the preset initial weight of the encrypted data block. A signature is obtained by binding the root node of the H-MHT tree with a private key. The signature and the encrypted data block are stored in a public cloud. The key-encrypted data is then processed into blocks and distributed and stored in a private cloud using the Shamir key-sharing algorithm. Here, N is a positive integer greater than 2. In response to a user's deletion operation, a deletion request is sent to both the private cloud and the public cloud, so that the private cloud randomly deletes a first preset number of key ciphertext blocks in the main storage node of key management, and the public cloud deletes the data ciphertext.

2. The method as described in claim 1, characterized in that, Determining the homomorphic hash value of the data ciphertext block based on homomorphic hashing rules includes: The encrypted data block is divided into M basic storage blocks based on the homomorphic hashing rule, where M is a positive integer less than N; The sum of the numerical values ​​of the M basic storage blocks is used as the homomorphic hash value of the data ciphertext block.

3. A method for deleting data, characterized in that, Applied to private clouds, including: After receiving the ciphertext of the block processing key sent by the user, the ciphertext of the block processing key is distributed and stored using the Shamir key sharing algorithm; Upon receiving a deletion request from the user terminal, a first preset number of key ciphertext blocks are randomly deleted from the main storage node of key management; After verifying the integrity of the key ciphertext in the primary storage node, if less than a second preset number of key ciphertext blocks are obtained or no key ciphertext blocks are obtained, a deletion success message is sent to the user terminal; if more than or equal to the second preset number of key ciphertext blocks are obtained, a deletion failure message is sent to the user terminal. The Redis Sentinel mechanism is used to switch between primary and secondary storage nodes. A first preset number of key ciphertext blocks are randomly deleted from the switched primary storage node. After verifying the integrity of the key ciphertext in the switched primary storage node, if less than a second preset number of key ciphertext blocks are obtained or no key ciphertext blocks are obtained, a deletion success message is sent to the user terminal.

4. The method as described in claim 3, characterized in that, After sending a successful deletion message to the user's client, the process also includes: The Redis Sentinel mechanism is used to verify the root value of the corresponding H-MHT tree in each slave storage node. If the root value is different from the root value of the corresponding H-MHT tree in the master storage node, data synchronization is performed on the slave node.

5. A data deletion device, characterized in that, include: The encryption unit is used to encrypt data based on a symmetric encryption algorithm to obtain data ciphertext, and to encrypt the key used to encrypt the data based on an asymmetric encryption algorithm to obtain key ciphertext. The processing unit is used to convert the encrypted data into binary form and perform inversion processing, divide the inverted encrypted data into N equal parts to obtain N encrypted data blocks; for any encrypted data block, determine the homomorphic hash value of the encrypted data block based on the homomorphic hash rule; An H-MHT tree is constructed based on the homomorphic hash value of the encrypted data block and the preset initial weight of the encrypted data block. A signature is obtained by binding the root node of the H-MHT tree with a private key. The signature and the encrypted data block are then stored in a public cloud. The ciphertext of the key is processed into blocks and then distributed and stored in a private cloud using the Shamir key-sharing algorithm; where N is a positive integer greater than 2. The request unit is used to respond to the user's deletion operation and send deletion requests to both the private cloud and the public cloud, so that the private cloud randomly deletes a first preset number of key ciphertext blocks in the main storage node of key management, and the public cloud deletes the data ciphertext.

6. A data deletion device, characterized in that, include: The storage unit is used to distribute the ciphertext of the block processing key sent by the user terminal in a distributed manner using the Shamir key sharing algorithm after receiving the ciphertext of the block processing key. The deletion unit is used to randomly delete a first preset number of key ciphertext blocks in the main storage node of key management after receiving a deletion request sent by the user terminal. The verification unit is used to verify the integrity of the key ciphertext in the master storage node. If less than a second preset number of key ciphertext blocks are obtained or no key ciphertext blocks are obtained, a deletion success message is sent back to the user terminal. If more than or equal to the second preset number of key ciphertext blocks are obtained, a deletion failure message is sent back to the user terminal. The master-slave storage node is switched using the Redis Sentinel mechanism. A first preset number of key ciphertext blocks are randomly deleted from the master storage node after the switch. After verifying the integrity of the key ciphertext in the switched primary storage node, if less than the second preset number of key ciphertext blocks are obtained or no key ciphertext blocks are obtained, a message indicating successful deletion is sent to the user terminal.

7. An electronic device, characterized in that, Including memory and processor; The memory is used to store instructions; The processor is configured to execute instructions stored in the memory, and when the processor executes the instructions stored in the memory, causes the electronic device to perform the method as described in any one of claims 1-4.

8. A computer storage medium, characterized in that, The computer storage medium stores instructions that, when executed on the computer, cause the computer to perform the method as described in any one of claims 1-4.

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