TWM591647U - Data management system capable of securely accessing and deleting data - Google Patents

Abstract

In a data management system, the management server performs the following operations: divides the data file into N sub-files in a predetermined division method and obtains the main eigenvalue of the data file using a predetermined hash algorithm; generates destruction related to the destruction of the data file The key, and N keys for encryption or decryption of the N sub-files, respectively, and output the destruction key and the N keys; according to a predetermined access protocol and using blockchain technology, store the corresponding The destruction key, the main eigenvalue and the N keys of the data file; using a predetermined symmetric encryption and decryption algorithm, encrypt each sub-file with the corresponding key to obtain N encrypted sub-files; and The N keys and the N encrypted sub-files are stored in a corresponding manner, and the retrieval and destruction of data files are performed.

Description

Data management system capable of safely accessing and deleting data

The present invention relates to data access, especially a data management system capable of safely accessing and deleting data.

In existing data storage systems that use blockchain technology, such as the Ethereum (Ethereum) system, the Ethereum Virtual Machine (EVM) simply compiles the data to be stored and verified without error It is then stored in the block, but it is not encrypted. Therefore, each node terminal of the Ethereum system can easily provide the data stored in the block through a simple decompile. On the other hand, the hash calculation of the Ethereum system for data verification before storing each data consumes relatively large system resources, and therefore has the disadvantages of slower processing speed and higher cost.

Therefore, especially for private document data, how to use the Ethereum blockchain technology to safely access and delete data is one of the current important research and development topics, and it has also become a goal that needs to be improved in related fields.

Therefore, the purpose of the present invention is to provide a data management system which can overcome at least one disadvantage of the prior art.

Therefore, a data management system provided by the present invention is used to manage a data file, and includes a file server and M (M≧1) management servers. The file server provides a file database. Each management server is connected to the file server, and includes a user interface module for providing a web-based user interface, a storage module, and a connection to the user interface module and the storage module , And at least a processing module with a predetermined access protocol is installed.

For each management server, when the processing module receives a management request containing the data file through the user interface, the processing module performs the following operations: dividing the data file into N in a predetermined division manner Sub-files, and use a predetermined hash algorithm to process the original data content of the data file and the data content of the N sub-files to obtain a hash value as the main eigenvalue of the data file, and N as the A hash value of N sub-eigenvalues of N sub-files; generate a destruction key related to the destruction of the data file, and N keys that are different from each other and used to encrypt or decrypt the N sub-files respectively, and respond to The management request outputs the N keys and the destruction key through the user interface; according to the predetermined access protocol and using blockchain technology, the destruction key corresponding to the data file and having correlation with each other , The main eigenvalue and the N keys, and the N keys and the N sub-eigenvalues in correspondence with each other are stored in a data block of the storage module; using a predetermined symmetric encryption and decryption algorithm, Encrypt each of the N sub-files with one of the N keys to obtain N encrypted sub-files corresponding to the N keys; and the N sub-files that have a corresponding relationship with each other The characteristic value and the N encrypted sub-files are sent to the file server

The file server stores the N sub-feature values and the N encrypted sub-files corresponding to the received from the management server in the file database.

The effect of the present invention is that the data file is stored in the file server in the form of encrypted sub-files generated by cutting, grouping, and encryption processing, so the security of the data file in storage can be greatly improved. When the management server receives N input codes that are the same as N keys at the same time, it verifies the N encrypted sub-files retrieved from the file server by the main hash value stored in the data block After the correctness (not tampered), the data file is output, and then all data related to the data file is completely erased according to the predetermined access protocol. In addition, the management server can also directly erase all data related to the data file when it receives the same input code as the destruction key.

Before the present invention is described in detail, it should be noted that in the following description, similar elements are denoted by the same number.

Referring to FIG. 1, the illustrated data management system 100 of the present embodiment is used to manage a data file, and includes a file server 1 connected to a communication network 200, and M (for example, M=3, but not limited to This) is connected to the management server 2 of the communication network 200. Therefore, each management server 2 is connected to the file server 1 via the communication network 200. However, in other embodiments, M may also be equal to 1 or other numbers. In this embodiment, it is worth noting that the management servers 2 are connected to each other via a communication network, and together constitute a blockchain system. In other words, each management server 2 can be used as a node terminal of this blockchain system. In actual use, if the communication network is a local area network, the blockchain system is a private chain mode blockchain system, and when the communication network is the Internet, the blockchain system is a Blockchain system of public chain mode.

Referring to FIG. 2, the file server 1 provides a file database 11. Each management server 2 is connected to the file server 1 and includes a user interface module 21, a storage module 22, and a processing module 23 connecting the user interface module 21 and the storage module 22 . In this embodiment, for each management server 2, the user interface module 21 is used to provide a web-based user interface (for example, an operation webpage that can be operated by a user), the processing module 23 Install a predetermined access protocol (for example, a smart contract related to file management) and a predetermined destruction protocol (for example, a smart contract related to file destruction). In use, when a user terminal (for example, a computer device or mobile device) 300 is connected to the management server 2, the processing module 23 imports the user terminal 300 to the operation webpage. For example, the operation webpage can be designed to include an operation interface area associated with application file management, file retrieval, file destruction, etc. The operation interface area can be operated by human input to obtain any input from the user terminal Information or uploaded files, but not limited to this example.

Hereinafter, referring to FIG. 2 and FIG. 3, an example will be described to explain how the data management system 100 can be combined with a user terminal (for example, the user terminal 400 shown in FIG. 2) when the user wants to apply for the management service of the data file Perform a file storage procedure. For example, the data file is a contract document related to, for example, four co-contractors, but not limited to this example. Before executing the file storage procedure, the user must first use the user terminal 400 to establish a communication connection with one of the management servers 2 (as shown in FIG. 2). The file storage procedure includes the following steps S301-S307.

When the user terminal 400 is connected to the management server 2, the processing module 23 imports the user terminal 400 to the user interface (ie, the operation web page) (step S301).

Then, in step S302, the user terminal 400 transmits a management request to the management server 2 through the operation of the user interface. In this embodiment, the management request includes a quantity N and the data file. For example, the number N is the same as the number of contractors in this contract document, that is, N=4, but not limited to this example. In other embodiments, the number N may also be other integer values determined by the applicant of the management service.

When the processing module 23 of the management server 2 receives the management request via the user interface, in step S303, the processing module 23 divides the data file into N (N=4) in a predetermined division manner ) Sub-files, and use a predetermined hash algorithm to process the original data content of the data file and the respective data content of the N sub-files to obtain a hash value as the main eigenvalue of the data file, and N respectively as The hash value of the N sub-eigenvalues of the N sub-files. More specifically, in this embodiment, the processing module 23 performs the following operations according to the predetermined splitting method: sequentially cutting the data content of the data file into multiple data segments with a predetermined data length; And using a predetermined grouping method, the data segments are divided into N data segment groups, and the data segments contained in each data segment group are combined to obtain the N sub-files. The predetermined data length can be obtained, for example, through calculation using the number N as a seed, but not limited to this. The predetermined hash algorithm is, for example, SHA (Secure Hash Algorithm) 256, but it is not limited to this. The predetermined grouping method divides the [(4×i)+1] data segment into the first data segment group; the [(4×i)+2] data segment into the second data segment group; The [[4×i]+3] data segment is divided into the third data segment group; and the [(4×i)+4] data segment is divided into the fourth data segment group, where i=0,1 ,..., but not limited to this.

In step S304, the processing module 23 generates a destruction key related to the destruction of the data file, and N are different from each other, respectively, in a random manner that is seeded by N and the current time point (Seed) The key used to encrypt or decrypt the N sub-files, and in response to the management request, output the N keys and the destruction key to the user terminal 400 via the user interface for the user terminal 400 display. In this case, for example, the four contractors can respectively hold the N (N=4) keys displayed on the user terminal 400 (for example, the keys can be stored on a pen drive) Used in subsequent retrieval operations; and, for example, one of the four contractors or other important related parties retain the destruction key displayed on the user terminal 400 for use in subsequent destruction operations, but not Examples are limited. In this embodiment, the destruction key and the keys are, for example, a 40-bit code composed of numbers and characters, but not limited to this example.

In step S305 following steps S303 and S304, the processing module 23 uses the block chain technology according to the predetermined access protocol to associate the destruction key and the main feature value that are related to the data file and are related to each other And the N keys, and the N keys and the N sub-characteristic values having a corresponding relationship with each other are stored in a data block (not shown) of the storage module 22. In addition, the management server 2 broadcasts the destruction key, the main feature value, and the N keys that are related to each other to the other (M-1) management servers 2 so that the other 2 (= 3-1) Each management server 2 stores the destruction key, the main feature value, and the N keys that are related to each other in a data block of the corresponding storage module.

For example, if the above example is followed, K11, K12, K13, and K14 represent the (four) keys; SK1 represents the destruction key; HASH10 represents the main eigenvalue; HASH11, HASH12, HASH13 and HASH14 respectively represent the (four) sub-eigenvalues corresponding to K11, K12, K13, and K14, respectively, after step S305, the data in the storage module 22 of each management server 2 The block can store the associated destruction key SK1, the main eigenvalue HASH10 and the keys K1, K2, K3, and K4, and the corresponding relationships in the form of a table as shown in FIG. 7 The keys K1, K2, K3, K4 and the sub-characteristic values HASH1, HASH2, HASH3, HASH4, but not limited to this example.

Afterwards, in step S306, the processing module 23 uses a predetermined symmetric encryption and decryption algorithm (for example, AES (Advanced Encryption Standard) 256, but not limited to this) to assign each of the N sub-files to the N One of the keys is encrypted to obtain N encrypted sub-files respectively corresponding to the N keys, and the management server 2 will respectively correspond to the N sub-eigenvalues of the N keys, and The N encrypted sub-files corresponding to the N keys are sent to the file server 1 respectively.

Finally, in step S307, the file server 1 stores the N sub-feature values and the N encrypted sub-files received from the management server 2 in the file database 11 in a corresponding manner. For example, if the above example is followed, in the case where FILE11, FILE12, FILE13, and FILE14 represent the (four) encrypted sub-files, respectively, the file database 11 may be stored in the form of a table as shown in FIG. 8 The sub-eigenvalues HASH1, HASH2, HASH3, HASH4 and the encrypted sub-files FILE11, FILE12, FILE13 and FILE14. At this point, the file storage process is completed.

Hereinafter, referring to FIG. 2, FIG. 4 and FIG. 5 will be exemplified when the user (for example, one or more contractors of the above contract document, but not limited to this example) wants to retrieve the data file to terminate When managing services, how does the data management system 100 integrate with a user terminal (for example, the user terminal 400 shown in FIG. 2 may be different from another terminal device used in the above file storage procedure in actual use) to Perform a file retrieval procedure. Before executing the file retrieval procedure, the user must first use the user terminal 400 to establish a communication connection with one of the management servers 2 (as shown in FIG. 2). In this case, the management server 2 connected to the user terminal 400 will be used as a retrieval starting server hereinafter, and the processing modules 23 mentioned below all refer to the processing module 23 of the destruction starting server 2. The file retrieval procedure includes the following steps S401-S416.

Similar to step S301 (FIG. 3) of the file storage procedure, when the user terminal 400 is connected to the retrieval starting server 2, the processing module 23 imports the user terminal 400 to the user interface (ie, the operation Web page) (step S401).

Then, in step S402, the user terminal 400 transmits a retrieval request to the management server 2 through the operation of the user interface. In this embodiment, the retrieval request includes N (for example, N=4) input codes.

After that, when the processing module 23 receives the retrieval request through the user interface, in step S403, the processing module 23 confirms whether there is a match with the N in the data block of the storage module 22 N keys of input codes. If the confirmation result is affirmative, the flow will proceed to step S405; otherwise, the retrieval activation server 2 transmits an input code error message to the user terminal 400 via the user interface (step S404). In other words, only when the N input codes entered by the user are the N keys stored in the data block can the following steps be continued, otherwise steps S402-S404 must be re-executed until the processing module 23 confirms the The N input codes are the N keys stored in the data block.

In step S405, the retrieval triggering servo 2 sends a file request including the N sub-feature values stored in the data block and corresponding to the N keys to the file server 1 respectively.

Then, in step S406, the file server 1 responds to the file request and sends the N encrypted sub-files stored in the file database 11 and corresponding to the N sub-eigenvalues to the retrieval starting server 2 .

When the retrieval starting server 2 receives the N encrypted sub-files from the file server 1, in step S407, the processing module 23 uses the predetermined symmetric encryption and decryption algorithm to use the N input codes ( That is, the N keys) respectively decrypt the received N encrypted sub-files to obtain N decrypted sub-files.

Then, in step S408, the processing module 23 uses a pre-grouping method corresponding to the predetermined grouping method to combine the data content contained in the N decrypted sub-files to obtain a combined data content.

Thereafter, in step S409, the processing module 23 processes the combined data content using the predetermined hash algorithm to obtain a hash value.

Then, in step S410, the processing module 23 determines whether the hash value is the same as the data block stored in the storage module 22 and associated with the N keys according to the predetermined access protocol Eigenvalues. If the judgment result is positive, this means that the combined data content is indeed exactly the same as the original data content of the data file (that is, the N encrypted sub-files provided by the file server 1 have not been tampered with) , The flow will proceed to step S412); otherwise, the retrieval and activation server 2 transmits a file error message to the user terminal 400 via the user interface (step S411).

In step S412, the processing module 23 uses the combined data content as the original data content (ie, the data file) and transmits it to the user terminal 400 through the user interface.

Then, in step S413, the processing module 23 deletes the previously stored related destruction key, the main feature value and the N number from the data block of the storage module 22 according to the predetermined access protocol The key, and the N keys and the N sub-eigenvalues that have a corresponding relationship. For example, in this case, the data in the list in FIG. 7 (ie, SK1, K11, K12, K13, K14, HASH10, HASH11, HASH12, HASH13, and HASH14) will be completely smeared.

Then, in step S414, the retrieval activation server 2 sends a deletion request to the file server 1 regarding the N sub-feature values and the N encrypted sub-files with corresponding relationships. Therefore, afterwards, in step S416, the file server 1 deletes the previously stored N sub-feature values and the N encrypted sub-files from the file database 11 in response to the received delete request. For example, in this case, the data in the list of FIG. 8 (that is, HASH11, HASH12, HASH13, and HASH14, and FILE11, FILE12, FILE13, and FILE14) will be completely erased.

On the other hand, in step S415 following step S413, the retrieval activation server 2 broadcasts the deletion message about the destruction key, the main feature value, and the N keys to other (M-1) Management server 2 (for example, the other two management servers 2). Therefore, the other (M-1) management servers each delete the related destruction key, the main feature value, and the N keys from the corresponding data block according to the predetermined access protocol, and have a corresponding relationship The N keys and the N sub-eigenvalues, thereby achieving consistency of the data stored in the data blocks of the data management server 2. At this point, the file retrieval process is completed.

The following will refer to FIGS. 2 and 6 to illustrate if the user (for example, a contractor of the above contract document, but not limited to this example) wants to if the above file retrieval procedure has not been executed When the data file is destroyed, when the repairer of the terminal equipment is dispatched to a repairer of the merchant to complete the repair application, how does the data management system 100 integrate with a user terminal (for example, the user terminal 400 shown in FIG. 2, In actual use, it may be different from the above-mentioned file storage procedure or file retrieval procedure used in another terminal device) to execute a file destruction procedure. Before performing the file destruction procedure, the user must first use the user terminal 400 to establish a communication connection with one of the management servers 2 (as shown in FIG. 2). In this case, the management server 2 connected to the user terminal 400 will be referred to as the destruction starting server hereinafter, and the processing modules 23 mentioned below all refer to the processing module 23 of the destruction starting server 2. The file destruction procedure includes the following steps S601-S608.

Similar to step S401 (FIG. 4) of the file retrieval procedure, when the usage terminal 400 is connected to the destruction activation server 2, the processing module 23 of the destruction activation server 2 imports the usage terminal 400 to the usage User interface (ie, the operation web page) (step S601).

Then, in step S602, the user terminal 400 transmits a destruction request to the destruction activation server 2 through the operation of the user interface. In this embodiment, the destruction request includes an input code.

After that, when the processing module 23 receives the destruction request via the user interface, in step S603, the processing module 23 determines whether there is a match in the input code in the data block of the storage module 22 The destruction key. If the determination result is affirmative, the flow proceeds to step S605; otherwise, the destruction activation server 2 transmits an input code error message to the user terminal 400 via the user interface (step S604). In other words, only when the input code entered by the user is the destruction key stored in the data block can the following steps be continued, otherwise steps S602-S604 must be re-executed until the processing module 23 determines that the input code is The destruction key stored in the data block.

In step S605, similar to step S413 (FIG. 5) of the file retrieval procedure, the processing module 23 deletes the associated destruction key from the data block of the storage module 22 according to the predetermined destruction protocol , The main eigenvalue and the N keys, and the N keys and the N sub-eigenvalues with corresponding relationships, thereby achieving erasure of the data block.

Then, in step S606, similar to step S414 of the file retrieval process (FIG. 5), the destruction activation server 2 deletes the N sub-feature values and the N encrypted sub-files that have corresponding relationships The request is sent to the file server 1. Subsequently, in step S608, similar to step S416 of the file retrieval process, the file server 1 deletes the previously stored N sub-feature values and the file from the file database 11 in response to the received delete request N encrypted sub-files, thereby achieving erasure of the file database 11.

On the other hand, in step S607 following step S605, similar to step S414 (FIG. 5) of the file retrieval procedure, the retrieval activation server 2 will relate the destruction key, the main feature value and the N The deletion message of each key is broadcast to the other (M-1) management servers 2 (for example, the other two management servers 2). Therefore, the other (M-1) management servers each delete the related destruction key, the main feature value, and the N keys from the corresponding data block according to the predetermined access protocol, and have a corresponding relationship The N keys and the N sub-eigenvalues, thereby achieving consistency of the data stored in the data blocks of the data management server 2. At this point, the file destruction process is completed.

In summary, since the data file is stored in the file server 1 in the form of encrypted sub-files generated by cutting, grouping, and encryption processing, the security of the data file in storage can be greatly improved. When the retrieval start server 2 receives N input codes that are the same as N keys at the same time, it verifies the N retrieved from the file server 1 by the main hash value stored in the data block After the correctness (not tampered) of an encrypted sub-file, the data file is output, and then all data related to the data file is completely erased according to the predetermined access protocol. In addition, the destruction activation server 2 can also directly erase all data related to the data file when receiving the input code that is the same as the destruction key. Therefore, it can really achieve the purpose of new cost.

However, the above are only examples of the new model. When the scope of the new model cannot be limited by this, any simple equivalent changes and modifications made according to the patent application scope and patent specification content of the new model are still regarded as Within the scope of this new patent.

100: data management system

1: File server

11: File database

2: management server

21: User interface module

22: Storage module

23: Processing module

200: communication network

300: Blockchain system

400: use terminal

S301~S307: Steps

S401~S416: Steps

S601~S608: Steps

Other features and functions of the present invention will be clearly presented in the embodiments with reference to the drawings, in which: FIG. 1 is a block diagram exemplarily illustrating the architecture of a data management system according to an embodiment of the present invention; FIG. 2 is a schematic diagram exemplarily illustrating a management server, a file server, and a user terminal when the embodiment is used; FIG. 3 is a flow chart exemplarily illustrating how this embodiment executes a file storage procedure; 4 and 5 are flow charts, which exemplarily illustrate how to perform a file retrieval procedure in this embodiment; FIG. 6 is a flow chart exemplarily illustrating how to perform a file destruction procedure in this embodiment; 7 is a schematic diagram exemplarily illustrating the content stored in the data block in this embodiment; and FIG. 8 is a schematic diagram exemplarily illustrating the content stored in the file database in this embodiment.

100: data management system

1: File server

2: management server

200: communication network

300: Blockchain system

Claims (9)

A data management system is used to manage a data file, and includes: A file server, providing a file database; and M (M≧1) management servers, each of which is connected to the file server and includes A user interface module for providing a web-based user interface, A storage module, and A processing module, connected to the user interface module and the storage module, and installed with at least a predetermined access protocol; For each management server, when the processing module receives a management request including the data file through the user interface, the processing module performs the following operations The data file is divided into N sub-files in a predetermined division method, and a predetermined hash algorithm is used to process the original data content of the data file and the respective data content of the N sub-files to obtain a master file as the data file The hash value of the eigenvalue, and N hash values of the N sub-eigenvalues of the N sub-files, Generate a destruction key related to the destruction of the data file, and N different keys used for encryption or decryption of the N sub-files respectively, and respond to the management request by outputting the N through the user interface Keys and the destruction key, According to the predetermined access protocol and using blockchain technology, the destruction key, the main eigenvalue and the N keys corresponding to the data file and related to each other, and the N keys corresponding to each other The key and the N sub-eigenvalues are stored in a data block of the storage module, Use a predetermined symmetric encryption and decryption algorithm to encrypt each of the N sub-files with one of the N keys to obtain N encrypted sub-files corresponding to the N keys, and Sending the N sub-eigenvalues and the N encrypted sub-files that have a corresponding relationship to each other to the file server; and Wherein, the file server stores the N sub-eigenvalues and the N encrypted sub-files corresponding to the received from the management server in the file database. The data management system according to claim 1, wherein the processing module of the management server performs the following operations according to the predetermined division method: Cut the data content of the data file into multiple data segments in sequence with a predetermined data length; and Using a predetermined grouping method, the data segments are divided into N data segment groups, and the data segments contained in each data segment group are combined to obtain the N sub-files. The data management system according to claim 1 or 2, wherein, in the case of M≧2, each management server is used as a node terminal of a blockchain system, and the management servers will also be associated with each other The destruction key, the main feature value and the N keys, and the corresponding N sub-feature values and the N encrypted sub-files are broadcast to other (M-1) management servers, so that The other (M-1) management servers will each have the destruction key, the main feature value, and the N keys that are related to each other, and the N sub-feature values and the N encrypted sub-files that have corresponding relationships A data block stored in the corresponding storage module. The data management system according to claim 3, wherein one of the M management servers is used as a management server for retrieving the starting server, and when the processing module receives a N input through the user interface When the code is retrieved, the processing module performs the following operations: When it is confirmed that the N input codes respectively match the N keys stored in the data block of the storage module, a N including the N keys stored in the data block and corresponding to the N keys respectively A file request for a sub-feature value is sent to the file server, so that the file server responds to the file request and sends the N encrypted sub-files stored in the file database and corresponding to the N sub-feature values to The retrieval server should be retrieved; When receiving the N encrypted sub-files from the file server, use the predetermined symmetric encryption and decryption algorithm to decrypt the received N encrypted sub-files with the N input codes, respectively, to obtain N decrypted sub-files file; Use a predetermined combination method corresponding to the predetermined grouping method to combine the data content contained in the N decrypted sub-files to obtain a combined data content; Processing the content of the combined data using the predetermined hash algorithm to obtain a hash value; According to the predetermined access protocol, determine whether the hash value is the same as the main feature value stored in the data block of the storage module and associated with the N keys; and When it is determined that the hash value is the same as the main eigenvalue, the combined data content is used as the original data content and output through the user interface, and deleted from the data block of the storage module according to the predetermined access protocol The previously stored correlation destruction key, the main feature value and the N keys, and the corresponding N keys and the N sub-feature values. The data management system according to claim 4, wherein, after the original data content is output, the retrieval starting server will also have information about the N sub-eigenvalues and the N encrypted sub-files with corresponding relationships The delete request is sent to the file server, so that the file server deletes the previously stored N sub-feature values and the N encrypted sub-files from the file database in response to the received delete request. The data management system according to claim 4, wherein, in the case of M≧2, the retrieval activation server will also provide information about the destruction key, the main feature value, the N keys, and the N sub-features The value deletion message is broadcast to other (M-1) management servers, so that the other (M-1) management servers each delete the associated destruction password from the corresponding data block according to the predetermined access protocol The key, the main eigenvalue and the N keys, and the N keys and the N sub-eigenvalues that have a corresponding relationship. The data management system as described in claim 3, wherein: The processing module of each management server is also installed with a predetermined destruction agreement; and For one of the M management servers to serve as the management server for the destruction start server, when the processing module receives a destruction request including an input code through the user interface, the processing module performs the following operations: According to the predetermined destruction agreement, determine whether the input code matches the destruction key stored in the data block; and When it is determined that the input code matches the destruction key, delete the associated destruction key, the main characteristic value and the N keys from the data block of the storage module according to the predetermined destruction protocol, And the N keys and the N sub-eigenvalues that have a corresponding relationship. The data management system according to claim 7, wherein in the case of M≧2, the destruction activation server also broadcasts the deletion information about the destruction key, the main characteristic value, and the N keys to other (M-1) management servers, so that the other (M-1) management servers each delete the related destruction key and the main feature from the data block of the corresponding storage module according to the predetermined destruction protocol Value and the N keys, and the N keys and the N sub-eigenvalues that have a corresponding relationship. The data management system according to claim 7, wherein, after the processing module determines that the input code matches the destruction key, the destruction activation server will also have information about the N sub-features with corresponding relationships The value and the delete request of the N encrypted sub-files are sent to the file server, so that the file server deletes the previously stored N sub-feature values and the N from the file database in response to the received delete request Sub-files.

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