WO2022222786A1

WO2022222786A1 - File storage method and apparatus, and device

Info

Publication number: WO2022222786A1
Application number: PCT/CN2022/086300
Authority: WO
Inventors: 印明亮; 余珊; 王凯
Original assignee: 支付宝(杭州)信息技术有限公司; 蚂蚁区块链科技(上海)有限公司
Priority date: 2021-04-20
Filing date: 2022-04-12
Publication date: 2022-10-27
Also published as: CN113065169A; CN116579025A; CN113065169B

Abstract

A file storage method and apparatus, and a device. The method comprises: acquiring a target file to be stored (210); according to a pre-set splitting mode, splitting the target file to obtain a plurality of pieces of split file data (220); according to a pre-set division mode, dividing the plurality of pieces of file data into a plurality of file sets (230); calculating check codes corresponding to the plurality of file sets (240); determining positioning file data information in each file set (250); and storing the check codes and the positioning file data information in a blockchain network (260).

Description

Method, device and equipment for document preservation

technical field

The present application relates to the field of blockchain technology, and in particular, to a method, device and equipment for document storage.

Background technique

Blockchain is a new application mode of computer technology such as distributed data storage, point-to-point transmission, consensus mechanism, and encryption algorithm. In the blockchain system, the data blocks are sequentially connected to form a chain data structure according to the time sequence, and a distributed ledger that cannot be tampered with and cannot be forged by cryptography. It is essentially a decentralized distributed database system participated by nodes. Because the blockchain has the characteristics of decentralization, non-tampering of information, and autonomy, the use of blockchain to store document data has also received more and more attention and applications.

SUMMARY OF THE INVENTION

The embodiments of the present specification provide a method, device and device for document storage, so as to solve the problem of difficulty in locating tampered data in a file in existing document storage and verification methods.

In order to solve the above technical problems, the embodiments of this specification are implemented as follows: a method for document storage provided by the embodiments of this specification includes: acquiring a target file to be stored; splitting to obtain multiple split file data; dividing the multiple file data into multiple file sets according to a preset division method; each of the file sets contains m elements; calculating the multiple file sets Corresponding check code; determine the positioning file data information in each of the file sets; the positioning file data information includes the position information of the positioning file data in the file set in the target file and the positioning file The content information of the data; the check code and the data information of the positioning file are stored in the blockchain network.

A file verification method provided by the embodiments of this specification includes: obtaining from a blockchain network the positioning file data information and a check code corresponding to the file to be verified; The multiple file sets are calculated by splitting the target file according to the preset splitting method to obtain multiple file data, and dividing the multiple files according to the preset splitting method. obtained by dividing the data; the positioning file data information includes the position information of the positioning file data in the file set in the target file and the content information of the positioning file data; based on the positioning file data information, determine multiple file sets corresponding to the files to be verified; calculating the check codes corresponding to the multiple file sets; comparing the calculated check codes corresponding to the multiple file sets with those obtained from the blockchain network The verification codes are compared to obtain a comparison result; based on the comparison result, the document to be verified is verified.

A file certificate storage device provided by an embodiment of the present specification includes: a target file acquisition module for acquiring a target file to be stored for a certificate; a file data determination module for splitting the target file according to a preset splitting method to obtain the split multiple file data; the file set division module is used to divide the multiple file data into multiple file sets according to a preset division method; each of the file sets contains m elements; The verification code calculation module is used to calculate the verification codes corresponding to the multiple file sets; the location file data information determination module is used to determine the location file data information in each of the file sets; the location file data information includes: The location information of the location file data in the file set in the target file and the content information of the location file data; a data storage module for storing the check code and the location file data information in the area in the blockchain network.

A file verification device provided by the embodiments of this specification includes: a data acquisition module for acquiring, from a blockchain network, positioning file data information and a check code corresponding to a file to be verified; the check code is obtained by The multiple file sets corresponding to the target file in the certificate are calculated and obtained; the multiple file sets are obtained by splitting the target file according to the preset splitting method to obtain multiple file data, which are divided according to the preset splitting method. Obtained by dividing the plurality of file data; the location file data information includes the location information of the location file data in the file set in the target file and the content information of the location file data; the file set determines a module for determining multiple file sets corresponding to the files to be verified based on the positioning file data information; a check code calculation module for calculating the check codes corresponding to the multiple file sets; a comparison module, for comparing the calculated check codes corresponding to the multiple file sets with the check codes obtained from the blockchain network to obtain a comparison result; a verification module for comparing based on the comparison As a result, the document to be verified is verified.

A file certification device provided by an embodiment of the present specification includes: at least one processor; and a memory connected in communication with the at least one processor; wherein, the memory stores data that can be executed by the at least one processor The instruction is executed by the at least one processor, so that the at least one processor can: obtain the target file to be stored; The divided multiple file data; the multiple file data is divided into multiple file sets according to a preset division method; each of the file sets contains m elements; the check codes corresponding to the multiple file sets are calculated ; Determine the location file data information in each of the file sets; the location file data information includes the location information of the location file data in the file set in the target file and the content information of the location file data; The check code and the positioning file data information are stored in the blockchain network.

A file verification device provided by an embodiment of the present specification includes: at least one processor; and a memory connected in communication with the at least one processor; wherein, the memory stores a program executable by the at least one processor. instruction, the instruction is executed by the at least one processor, so that the at least one processor can: obtain the location file data information and check code corresponding to the file to be verified from the blockchain network; the check code It is obtained by calculating the multiple file sets corresponding to the pre-stored target files; the multiple file sets are splitting the target files according to the preset splitting method to obtain multiple file data, and according to obtained by dividing the plurality of file data by a preset division method; the location file data information includes location information of the location file data in the file set in the target file and content information of the location file data ; Based on the positioning file data information, determine multiple file sets corresponding to the document to be verified; Calculate the corresponding check codes of the multiple file sets; Calculate the corresponding check codes of the multiple file sets that are obtained Comparing with the check code obtained from the blockchain network to obtain a comparison result; and verifying the to-be-verified file based on the comparison result.

An embodiment of the present specification provides a computer-readable medium on which computer-readable instructions are stored, and the computer-readable instructions can be executed by a processor to implement a method for document storage and verification.

An embodiment of the present specification achieves the following beneficial effects: obtaining the target file to be stored; splitting the target file according to a preset splitting method to obtain multiple split file data; according to the preset splitting method Divide the multiple file data into multiple file sets; calculate the check codes corresponding to the multiple file sets, determine the location file data information in each file set, and store the check codes and the location file data information in the in the blockchain network. Through the method of storing the certificate on the block large file chain, it is not necessary to store all the data corresponding to the target file in the blockchain network, so as to avoid the defect of data expansion. Introducing check code and locating file data information, when the target file being certified is tampered with, the tampered data in the target file can be located.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present specification or the prior art, the following briefly introduces the accompanying drawings required in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments described in this application. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without any creative effort.

1 is a schematic diagram of an application scenario of a method for document storage and verification in the embodiment of this specification;

FIG. 2 is a schematic flowchart of a method for document storage provided in an embodiment of the present specification;

3 is a schematic diagram of the arrangement of file sets provided by the embodiment of the present specification;

FIG. 4 is a schematic flowchart of a method for document storage provided in an embodiment of the present specification;

5 is a schematic diagram of preliminary positioning based on positioning file data information provided by an embodiment of the present specification;

6 is a schematic diagram of supplementary positioning based on positioning file data information provided by an embodiment of the present specification;

7 is a schematic diagram of verification based on a check code provided by an embodiment of the present specification;

FIG. 8 is a schematic structural diagram of a file certificate storage device according to an embodiment of the present specification;

9 is a schematic structural diagram of a file verification device according to an embodiment of the present specification;

FIG. 10 is a schematic diagram of a document storage and verification device provided by an embodiment of the present specification.

Detailed ways

In order to make the objectives, technical solutions and advantages of one or more embodiments of this specification clearer, the technical solutions of one or more embodiments of this specification will be clearly and completely described below with reference to the specific embodiments of this specification and the corresponding drawings. . Obviously, the described embodiments are only some of the embodiments of the present specification, but not all of the embodiments. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments in the present specification without creative efforts fall within the protection scope of one or more embodiments of the present specification.

The technical solutions provided by the embodiments of the present specification will be described in detail below with reference to the accompanying drawings.

In the embodiments of this specification, the terms involved are explained as follows: Blockchain: "Blockchain" technology was originally developed by a pseudonym "Satoshi Nakamoto" for Bitcoin (a digital currency). A special distributed database technology designed can be understood as a data chain composed of sequential storage of multiple blocks. The block header of each block contains the timestamp of this block and the information of the previous block. The hash value and the hash value of the information of this block, thereby realizing the mutual verification between blocks and forming an immutable blockchain. Each block can be understood as a data block (unit of storing data). As a decentralized database, blockchain is a series of data blocks that are correlated with each other using cryptographic methods. Each data block contains the information of a network transaction, which is used to verify the validity of its information (anti-counterfeiting). and generate the next block. A chain formed by connecting blocks end-to-end is called a blockchain. If you need to modify the data in the block, you need to modify the content of all blocks after this block, and modify the data backed up by all nodes in the blockchain network. Therefore, the blockchain has the characteristics of being difficult to tamper and delete. After the data has been saved to the blockchain, it is reliable as a method to maintain the integrity of the content.

Hash algorithm: It transforms an input of arbitrary length (also called pre-image pre-image) into a fixed-length output through a hash algorithm, and the output is the hash value. This transformation is a compressed map, the space of the hash value is usually much smaller than the space of the input, and different inputs may hash to the same output, so it is impossible to determine the unique input value from the hash value. Can be a function that compresses a message of arbitrary length into a message digest of a fixed length. The more common ones are SHA256 and SM3 algorithms.

Erasure correction algorithm: It is a coding fault-tolerant technology. It was first used in the communication industry to solve the problem of loss of some data during transmission. The basic principle is to segment the transmitted signal, add a certain check, and then make a certain connection between the segments , even if part of the signal is lost during transmission, the receiver can still calculate the complete information through an algorithm. For example: an error correction code algorithm (Reed-Solomen, RS algorithm for short).

Due to the characteristics of blockchain distributed ledgers, each participant will have at least one piece of ledger data. In the existing blockchain-based document storage solutions, the document data is generally recorded directly on the blockchain, and the certificate is stored directly through the blockchain. Adopting the mode of directly uploading files to the chain will cause the problem of data expansion. Due to the limitation of the transaction size of the blockchain, the size of the file will be strictly limited, which is convenient for storing certificates, and there will also be potential security risks, which is not conducive to the development of blockchain technology.

On the other hand, some files contain sensitive information and are not suitable to be stored in the original text directly on the chain. Usually, for large files or sensitive files, the method of Hash on-chain is adopted: before the on-chain, a certain Hash algorithm is used to calculate the Hash value (digest value) of the file, and then the Hash value is uploaded to the chain to store the certificate. For example, using the SHA256 hash algorithm, pre-calculate the SHA256 value of the file that needs to be stored, and then upload the 32-byte SHA256 value to the chain; in this way, no matter how large the source file is, it will be irreversibly converted into a 32-byte digest.

However, when verifying the authenticity of the file, the file that needs to be verified is obtained from other systems, and the Hash value of the file is calculated again, and compared with the chain. When the Hash value is consistent, it means that the file has not been tampered with. , when the Hash value is inconsistent, it means that the file has been tampered with. In the scheme of Hash uploading large files, it is generally necessary to select hash algorithms with sufficient strength, such as SHA256, SM3 and other algorithms; avoid using algorithms with potential security risks, such as CRC, MD5, etc.

FIG. 1 is a schematic diagram of an application scenario of a method for document storage and verification in an embodiment of this specification. As shown in FIG. 1 , for the target file X to be certified, the target file X is analyzed to obtain the certification data X1 corresponding to the target file. The certification data X1 may include a digest value, a check code and positioning file data information. . The depository data X1 is stored in the blockchain network 110 . The original data X2 corresponding to the target file X can be stored in an external device 120 outside the blockchain network, such as a USB flash drive or other servers.

Next, a method for document depositing provided by the embodiments of the description will be described in detail with reference to the accompanying drawings:

Example 1

FIG. 2 is a schematic flowchart of a method for document storage provided by an embodiment of the present specification. From a program perspective, the execution body of the process may be a program mounted on an application server or an application client.

As shown in FIG. 2 , the flow may include the following steps: Step 210 : Obtain the target file to be stored.

Blockchain data storage can mean that data is stored on the blockchain to achieve the purpose of anti-tampering, traceability, and trustworthy data sources. In order to achieve fast transactions, in general, the on-chain and off-chain collaborative work is adopted, and the file and the hash value are separated. Only the hash value of the file is stored on the chain, and the original file is stored off-chain. As long as the hash value of the file is calculated and compared with the hash value on the chain, it is known whether the file has been tampered with. In the embodiment of this specification, the data in the target file to be certified may be in any file form such as text, video, audio and picture. The entire file data corresponding to the target file does not need to be stored in the blockchain network, only the corresponding data that can represent the target file needs to be stored.

Step 220: Splitting the target file according to a preset splitting manner to obtain multiple split file data.

It should be noted that the traditional understanding of splitting can be: the process of combining different parts of a whole and being separated separately is splitting. The mid-splitting in this step can be understood as: dividing the data constituting the target bit file into multiple file data in turn according to the byte length corresponding to the fixed file data, for example: there is data corresponding to 100 bytes in the target file, The target file can be split into 100 pieces of file data according to the splitting method of 1 byte for each small file data. Of course, every ten bytes can be a file data or element, that is, the data corresponding to the 1st to 10th bytes are marked as the first file data or the first element, and the 11th to 20th bytes are marked as the first file data or the first element. The data corresponding to each byte is marked as the second file data or the second element, ..., and so on, split the target file into multiple file data or multiple elements. The file data or elements obtained from the split are used for subsequent set division.

Step 230: Divide the multiple file data into multiple file sets according to a preset division method; each of the file sets includes m elements, where m≧1.

The preset division mode may represent the preset number of files included in each file set, for example, the preset division mode is that three files are one file set.

After the target file is divided into multiple file data or multiple elements, the multiple files are divided into multiple file sets according to a preset division method.

It should be noted that an element may represent one or more file data, specifically, an element may be file data. For example, for the target file X, it is divided into X1, X2, X3, and X4. When dividing, X1 , X2 are divided into set 1, and X3 and X4 are divided into set 2. Taking set 1 as an example, the elements in set 1 may be specific data corresponding to X1 and X2.

Of course, when the number of elements in each file set is set to be fixed, there may be a situation where the number of elements in the last set is not enough. In this case, fixed characters can be used to fill the missing elements in the set. Therefore, elements can also be fixed characters, eg: \×00.

Step 240: Calculate the check codes corresponding to the multiple file sets.

The check code can represent a piece of check data obtained by calculating on a certain length of original data through a certain algorithm (for example, a Hash algorithm or an erasure algorithm). By verifying the data, it can be determined whether the new data is consistent with the original data, and further, the original data can be deduced from the new data in which the original data has been slightly modified.

Therefore, for each file set, a Hash algorithm or an erasure algorithm can be used to calculate the check code corresponding to each file.

Step 250: Determine the location file data information in each of the file sets.

Optionally, the determining the location file data information in each of the file sets may specifically include: determining an element at a specific position in each group of the file sets as the location file data to obtain a location file data set.

The locating file data information may represent data information at a specific position in each file set, and more specifically, the locating file data information may include the position information of the locating file data in the file set in the target file and the content information of the positioning file data. The locating file data may also be referred to as a locating code. The location code may be an element in the file set, and the element may be one or more file data; after the target file is divided into multiple file sets, it can be roughly determined by the location code that the previously divided set is in the new data approximate location. For example, the first element in each set can be used for the positioning code. Suppose there are 9 elements in each set. According to the positioning code, it can be roughly determined that starting from the data corresponding to the positioning code, nine consecutive elements may belong to one File collection.

It should be noted that, in practical applications, the positioning file data may be the original data in the target file, or may be a value obtained by calculating the original data, for example, it may be a hash obtained by calculating the data used for positioning value or check value. In this way, when storing the location file data in the blockchain network, it is only necessary to store the calculated hash value or check value.

Step 260: Store the check code and the positioning file data information in the blockchain network.

When the target file is stored, not all the data corresponding to the entire target file is stored in the blockchain network, but the original data is stored on a device outside the blockchain network, for example, it can be stored in a mobile hard disk. The data that needs to be stored in the blockchain network is the check code obtained by analyzing and calculating the target file and the data information of the positioning file. Subsequently, the tampered data in the target file can also be located through the check code and the location file data information.

It should be understood that the order of some steps in the method described in one or more embodiments of this specification may be interchanged according to actual needs, or some steps may be omitted or deleted.

The method in FIG. 2 obtains the target file to be stored; splits the target file according to the preset splitting method to obtain multiple split file data; divides the multiple file data according to the preset splitting method at most a file set; calculate the check codes corresponding to the multiple file sets, determine the location file data information in each file set, and store the check code and the location file data information in the blockchain network. Through the method of storing the certificate on the block large file chain, it is not necessary to store all the data corresponding to the target file in the blockchain network, so as to avoid the defect of data expansion. Introducing check code and locating file data information, when the target file being certified is tampered with, the tampered data in the target file can be located.

Based on the method of FIG. 2 , some specific implementations of the method are also provided in the examples of this specification, which will be described below.

Optionally, the method may further include: using a hash algorithm to calculate a digest value of the target file; and storing the digest value in the blockchain network.

It should be noted that a digest value corresponding to the target file can also be stored in the blockchain network, and the digest value is obtained by calculating the target file by using a digest algorithm (also called a hash algorithm or a hash algorithm). The digest algorithm is used to prevent tampering. For example, assuming that the content in the target file is calculated by MD5, the internal digest value obtained is A1. During verification, if the digest value corresponding to the obtained file is B, which is different from the digest of the original text, it can be determined that the target file has been tampered with.

Since the digest function is a one-way function, the digest function f() is used to calculate a fixed-length digest value for data of any length, but it is difficult to deduce the original data through the digest value. Slight changes to the original data can result in completely different summaries. Therefore, if the digest value is changed, it can be determined that the original data has been tampered with.

In the above method, the digest value corresponding to the target file is calculated, and the digest value is stored in the blockchain network. Compare the digest values of , and if they are consistent, it can be determined that the target file has not been tampered with, and there is no need to perform the subsequent steps of locating the tampered data in the file. If the digest values are inconsistent, the solutions in the embodiments of this specification can be further used to locate the tampered data in the target file.

Optionally, the storing the check code and the positioning file data information in the blockchain network may specifically include: storing the digest value, the check code and all the data according to a preset splicing method. The positioning file data information is spliced to obtain the certificate data corresponding to the target file; and the certificate data is stored in the blockchain network.

It should be noted that, when the target file is stored for certification, the data stored in the blockchain network can be called certification data, and the certification data can include digest value, check code and positioning file data information. More specifically, the certificate data may be obtained by splicing the digest value, the check code and the location file data information. The splicing method may be sequential splicing, or may be splicing according to other preset methods.

In the above method, the certificate data corresponding to the target file is stored in the blockchain system, and the digest value in the certificate data can preliminarily determine whether the target file has been tampered with, and by locating the file data information, it can be determined that the target file is divided into the certificate when it is stored. File collection, the tampered data in the target file can be determined through the check code.

Optionally, the storing the deposit data in the blockchain network may specifically include: generating a deposit certificate including authentication information based on the deposit data; storing the deposit certificate including the deposit certificate Data is sent to the blockchain network for storage.

It should be noted that the deposit certificate can correspond to a network address and/or picture, which can be used to view the deposit certificate corresponding to the deposit data; the deposit certificate can be viewed according to the corresponding webpage or picture of the network address, and it can be displayed in the blockchain network. Validate the deposit certificate to ensure the authenticity of the deposit data.

Optionally, dividing the multiple file data into multiple file sets according to a preset division method may specifically include: dividing the multiple file data into N files according to the preset number of files in the file set. Collections; elements in each of said document collections have an order between them.

After the target file is divided into multiple file data, the multiple file data can be divided into multiple file sets. When dividing, the preset number of files in each file set (for example: in each file set The number of files is 5), and the data of multiple files is divided into multiple file sets.

The elements in each set can have an order. When the target file is split, it can be understood as determining the data corresponding to each byte in the target file. The split does not affect the original data in the target file. The split data will not be stored, and the splitting step is only used for the subsequent steps of dividing into sets. Therefore, multiple file data can be divided into multiple file sets in turn, for example: after splitting the target file The obtained file data is A1, A2, A3, A4, A5, A6, A7, A8, A9, A10, A11, A12, A13, A14. When dividing, it is assumed that the number of elements in each file set is 5 , then the sets obtained by dividing in order are: set 1 = {A1, A2, A3, A4, A5}, set 2 = {A6, A7, A8, A9, A10}, set 3 = {A11, A12, A13 , A14, \×00}.

In the above method, the file data is divided into multiple file sets in sequence, which is helpful for locating the location of the tampered data more quickly when verifying the tampered condition of the target file later.

Optionally, before calculating the check codes corresponding to the multiple file sets, the method may further include: arranging the N file sets in the form of a matrix to obtain a matrix with N rows and M columns; The check codes corresponding to the multiple file sets may specifically include: using an erasure correction algorithm to generate a corresponding check code for each row of the matrices corresponding to the multiple file sets; The corresponding check code is generated for each column of file collections.

In practical applications, after the target file is divided into multiple file sets, the multiple file sets can be arranged in the form of a matrix.

Description can be made with reference to FIG. 3 : FIG. 3 is a schematic diagram of arrangement of file sets provided in an embodiment of the present specification. As shown in FIG. 3 , multiple file sets can be labeled in sequence, for example: A ₁₁ , A ₁₂ , ..., A _1n , ..., A ₂₁ , A ₃₁ , ... , A _n1 , etc. Spliced into an N*N matrix, the value of N can be adjusted according to the specific situation. If there are remaining file sets, you can continue to label and concatenate into the next N*N matrix. When the file set is not enough to fill the last N*N matrix, use the file set composed of fixed characters, such as: \x00 to fill, as shown in the shaded part in Figure 3, some characters in A ₃₃ to A _nn are all It is filled with a set of files consisting of fixed characters. Among them, other fixed characters can also be selected for the fixed characters.

When calculating the check code, a check code can be selected, and the check code of each row and the check code of each column of the matrix in FIG. 3 can be calculated respectively. For example, the check code corresponding to the first row of the matrix in FIG. 3 The check code is RS ₁ , the check code corresponding to the second row is RS ₂ , the check code corresponding to the third row is RS ₃ , ..., the check code corresponding to the Nth row is RS _n ; the corresponding check code of the first column is RS n . The check code is RS _n+1 , the check code corresponding to the second column is RS _n+2 , the check code corresponding to the third column is RS _n+3 , ..., the check code corresponding to the Nth column is RS _n+n .

It should be noted that, when calculating the check code, the algorithm used is not limited to using the erasure algorithm, and other types of Hash algorithms can also be used.

When using the erasure algorithm, for example, when using the RS algorithm, take N(Data Shards)=50, Parity Shards=2, the original file (2/50)*2=8% of the information will be generated for erasure and correction. It can also ensure that any four file sets in the matrix can be tampered with and can still restore the original evidence data (up to two file sets per row or column).

Through the above method, when the document is stored for verification, the file is verified and stored in blocks, and a check code and a positioning code are introduced to correct errors during file verification. First divide the file into blocks, and then arrange each block into an n*n two-dimensional matrix in turn; calculate the check code for each row and each column of the matrix, and use the first element of each matrix as the positioning code; By writing the file digest check code and locating the file data information for storage on the blockchain, using a controllable storage cost, it is possible to determine which file sets in the large file have been modified and which are the original content, and can still be used. Provide proof of non-tampering of correct or missing parts.

Example 2

FIG. 4 is a schematic flowchart of a method for document storage provided by an embodiment of the present specification.

In the verification phase, it can detect which shards in the large file have been modified, and can still provide unmodified proofs for unmodified shards; further, if the number of modified shards is small, it can be pointed out in the verification phase that these shards have been modified. how to modify.

As shown in FIG. 4 , the process may include the following steps: Step 410 : Obtain the location file data information and check code corresponding to the file to be verified from the blockchain network.

Wherein, the check code can be obtained by calculating multiple file sets corresponding to the pre-stored target file; the multiple file sets can be divided according to the preset splitting method to obtain A plurality of file data is obtained by dividing the plurality of file data according to a preset division method; the positioning file data information may include the position information of the positioning file data in the file set in the target file and Content information of the location file data.

Specifically, for the relevant content involved in this step, reference may be made to the explanation in Embodiment 1, and details are not repeated here.

It should be noted that, in the verification stage, according to the file identifier of the document to be verified, the stored certificate data corresponding to the document to be verified is obtained from the blockchain network. Wherein, the certificate data may include the digest value of the to-be-verified file, the check code, and the location file data information. The digest value may be calculated on pre-certified target files.

Step 420: Determine multiple file sets corresponding to the to-be-verified file based on the location file data information.

In the verification stage, through the location file information stored in the blockchain network, the multiple file sets corresponding to the files to be verified can be determined according to the preset division method used in the certification stage.

More specifically, the location information in the locating file data information and the content information of the locating file data can roughly locate the elements of the file set corresponding to the file to be verified in the certification stage, for example: determine from the obtained locating file data information. In the certification stage, the first element in each file set is used as the positioning code, then the first element can be found in the file to be verified as the first element of the first set, and then according to each The number of fixed elements in the set, for example: 9, in the data corresponding to the file to be verified, find 9 elements in sequence starting from the first element, as the first set of files, and so on, to find out the possibility of the file to be identified The corresponding set of files. Finally, multiple file sets corresponding to the files to be verified are determined.

Step 430: Calculate the check codes corresponding to the multiple file sets.

When calculating the check codes corresponding to multiple file sets corresponding to the files to be verified, you can first arrange the multiple file sets in a matrix form, and calculate the check codes corresponding to each row of file sets in the matrix and calculate each column of files. Set the corresponding check code.

Step 440: Compare the calculated check codes corresponding to the multiple file sets with the check codes obtained from the blockchain network to obtain a comparison result.

Step 450: Verify the to-be-verified file based on the comparison result.

By comparing the check codes, it can be determined that the file set in a certain row and/or a certain column in the matrix has been tampered with. Therefore, the calculated check code can be compared with the check code obtained from the blockchain network, so as to locate the tampered file set.

The method in FIG. 4 obtains the location file data information and check code corresponding to the file to be verified from the blockchain network; based on the location file data information, multiple file sets corresponding to the to-be-verified file are determined; calculate Check codes corresponding to the multiple file sets; compare the calculated check codes corresponding to the multiple file sets with the check codes obtained from the blockchain network to obtain a comparison result; Based on the comparison result, the to-be-verified file is verified. The tampered data can be located by determining the specific set of tampered files in the files to be verified from the certificate data stored in the blockchain network.

Based on the method of FIG. 4 , some specific implementations of the method are also provided in the examples of this specification, which will be described below.

Optionally, the obtaining the location file data information and the check code corresponding to the file to be verified from the blockchain network may specifically include: obtaining identification information corresponding to the file to be verified; The positioning file data information and the check code corresponding to the to-be-verified file are obtained in the blockchain network.

It should be noted that the identification information can represent information that can uniquely identify the file to be verified. Based on the identification information, the storage data corresponding to the document to be verified can be obtained from the blockchain network. Further, in order to ensure the storage data Before obtaining the certificate data corresponding to the document to be verified based on the identification information, the requester requesting to obtain the certificate data corresponding to the document to be verified can be required to provide an authorization statement, and the authorization statement can be issued by the holder of the document to be verified. The specific address and the authorization statement issued by the party can carry the digital signature of the holder. When the blockchain network receives the request for obtaining the data of the deposit, it can review the authorization statement carried in the request for the data of the deposit. , the certificate data corresponding to the file to be verified can be provided to the requester based on the identification information in the request.

Optionally, before determining the multiple file sets corresponding to the to-be-verified file based on the locating file data information, the method may further include: calculating the digest value of the to-be-verified file by using the Hash algorithm used when storing the certificate. ; Compare the digest value of the described document to be verified that is calculated with the digest value in the data on record; When the digest value of the document to be verified calculated is consistent with the digest value in the data on record when the file to be verified has not been tampered with; when the calculated digest value of the file to be verified is inconsistent with the digest value in the certificate data, determine the file to be verified based on the location file data information A collection of multiple files corresponding to a file.

In practical applications, when verifying whether the file has been tampered with and the specific data that has been tampered with, it is possible to first determine whether the file has been tampered with. The digest values of the target files obtained in the blockchain network are compared, and if they are consistent, it can be determined that the file to be verified is the corresponding target file when the certificate is stored. data steps. On the contrary, if the digest values are inconsistent, it can be determined that the file to be verified is a tampered file, and the tampered specific data in the file to be verified can be further located.

Optionally, the determining, based on the location file data information, multiple file sets corresponding to the to-be-verified file may specifically include: determining a first location file data set based on the location information; based on a dynamic programming algorithm, Determine from the first positioning file set a second positioning file data set whose coverage satisfies a preset condition; compare the second positioning file data set with pre-stored positioning file data information to determine inconsistent positioning file data information; according to the inconsistent positioning file data information, determine a third positioning file data set, so that the matching rate between the third positioning file data set and the pre-stored positioning file data is maximized; based on the third positioning file data set, and multiple file sets corresponding to the to-be-verified file are determined.

It should be noted that the first positioning file data set may represent all possible positioning code sets determined according to fixed intervals, and the second positioning file data set is based on the dynamic programming algorithm, and the determined matrix coverage meets the preset conditions. The set of positioning codes. ; The third positioning file data set is the final positioning code set obtained after performing supplementary positioning on the second positioning file data set.

When determining multiple file sets based on the positioning file data information, the goal is to obtain the positioning code from the evidence data, and make the matrix determined by the positioning code in the verified file consistent with the matrix in the original file as much as possible. The corresponding stage can be divided into preliminary positioning and supplementary positioning: the preliminary positioning can be based on the fixed interval between the file sets when the certificate is stored. content as much as possible. It should be noted that, in practical applications, when there are multiple arrangements with the same coverage ratio, the overall matching ratio of the matrices determined by these arrangements can be further compared, and a positioning code arrangement with the highest matching ratio can be selected.

Specifically, the matching rate of each matrix=the number of unmodified file sets in the matrix/the total number of matrix file sets); description is made in conjunction with FIG. 5: FIG. 5 provides preliminary positioning based on the positioning file data information provided by the embodiment of this specification Schematic.

As shown in Figure 5, in the verified file, the intervals between A11 and B11, E11 and F11 and G11, and H11 and I11 are all fixed intervals when the certificate is stored; there is an unrelated location code between B11 and E11 C11, D11 and there are data not covered by the matrix determined by the positioning code; at the same time, the positioning code H11 is located inside the matrix determined by the positioning code G11.

Supplementary positioning can be a supplement to the preliminary positioning. When there is an undetermined positioning code in the positioning code sequence between the two determined positioning codes in the verified file, the supplementary positioning is responsible for inserting these positioning codes into these two positions of the verified file. Between certain positioning codes, the matching rate of each matrix is made as high as possible. Description will be made with reference to FIG. 6 : FIG. 6 is a schematic diagram of supplementary positioning based on positioning file data information provided by an embodiment of the present specification.

As shown in Figure 6, between the B11 and E11 positioning codes, the matrix determined by the two positioning codes C11 and D11 is inserted through complementary positioning. For example: record each positioning code as a ₁ ,a ₂ ,…,an , the size of the matrix determined by the positioning code when the certificate _is stored is L bytes, and the byte stream of the verified file is d ₁ ,d ₂ ,…,d _m . Traverse the file byte by byte, if [d _i , d _i+1 , d _i+2 , d _i+3 ]==a _j (assuming the file set is 4 bytes), and [d _i+L ,d _{i +L+1} ,d _i+L+2 ,d _i+L+3 ]==a _j+1 , [d _i+n*L ,d _i+n*L+1 ,d _{i+n*L+ 2} ,d _i+n*L+3 ]! =a _j+n ; then a _j ,a _j+1 ,...,a _j+n-1 is on [d _i ,d _i+1 ,...,d _i+(n-1)*L+3 ] Valid positioning interval. Note that all valid intervals on the verified file are arranged as S ₁ , S ₂ ,...,S _n in ascending order according to the byte stream position of the termination positioning code (d _i+(n-1)*L+3 ), and the length of each interval is X ₁ , X ₂ ,...,X _n . Length = number of positioning codes - 1, as well as the initial positioning code serial numbers a ₁ , a ₂ , ..., a _n of each interval and the end positions d ₁ , d ₂ , ..., dn in the verified file; then the problem is Converted to selecting interval sequence [S _R1 ,S _R2 ,...,S _Rm ] from S, satisfying a _i +X _i ≤a _i+1 , and maximizing X _R1 +X _R2 +...+X _Rm . This problem can be solved by the following dynamic programming when a _i +X _i ≤a _i+1 is ignored.

Specifically, it is possible to detect the adjustment of the data sequence in the verified file: denote dp[i] as the maximum coverage length to the i-th byte in the verified file, and Sk as the set of all valid intervals with i as the termination position , then the state transition equation is: when a _i +X _i ≤a _i+1 is added, the following two-dimensional dynamic programming can be used to solve it.

Furthermore, an interval sequence [S _R1 ,S _R2 ,…,S _Rm ] in S can be obtained, which satisfies a _i +X _i ≤a _i+1 , and maximizes X _R1 +X _R2 +…+X _Rm ; It is an arrangement of the positioning code in the original file according to the fixed interval of the positioning code when the certificate is stored, which can make the content covered by the matrix determined by the positioning code in the verified file as much as possible.

The undetermined positioning codes in the recording interval are a ₁ , a ₂ ,...,an , and the size of the matrix determined by the positioning codes when the certificate _is stored is L bytes. The first step is to look for the first positioning code a ₁ in the interval (if not found, then look for a ₂ , if not found, skip the supplementary positioning); the second step is to find a2 on the left and right of a ₁ +L (if not found) Then look for a3, the leftmost position on the left to a1, and the right side to the end of the interval); the third step repeats step 2 until the interval ends or there is no next undetermined positioning code. The location of the positioning code determined in the above three steps is the supplementary determined positioning code.

Optionally, the calculating the check codes corresponding to the multiple file sets may specifically include: arranging the N file sets in the form of a matrix to obtain a matrix with N rows and M columns; using an erasure correction algorithm, A corresponding row check code is generated for the multiple file sets corresponding to each row of the matrix; and a corresponding column check code is generated for the multiple file sets corresponding to each column of the matrix.

When calculating the check codes corresponding to multiple file sets, you can first determine the matrices corresponding to the multiple file sets, and then calculate the check codes corresponding to each row and each column in the matrix for the matrix: Specifically, starting from each positioning code (eg A11, B11, C11), divide the data following the positioning code according to the file data division method of each set (for example, 4 Bytes) when the certificate is stored, until the next positioning code. If the data cannot fill a file set until the next positioning code, the remaining part of the last file set will be filled with fixed bytes such as \x00 when the certificate is stored.

Through each positioning code and its corresponding file set, restore the N*N matrix used for depositing the certificate. If by the next positioning code, the number of data file sets exceeds the number of file sets in the evidence matrix N*N, the excess file sets will be regarded as inserted data marks; if the number of file sets is insufficient, the evidence The fixed bytes determined at the time such as \x00 fill the subsequent file set, make up the N*N matrix, and regard the missing file set as the missing data mark.

Then, when calculating the check codes of the multiple file sets corresponding to the files to be verified, the check codes or Hash functions are used to calculate the check codes of each row and column of each matrix, respectively, and the check codes of each row and column are calculated with the check codes when the certificates are stored. Compare the saved checksum to locate the modified file set. Description can be made with reference to FIG. 6 : FIG. 7 is a schematic diagram of verification based on a check code according to an embodiment of the present specification.

As shown in Figure 7, for example, when the check code of the matrix is calculated and compared with the check code obtained in the blockchain network, it is found that RS ₁ , RS ₃ , RS _n+1 , RS _n+n and the storage If the value of the check code in the certificate is inconsistent, it can indicate that the contents of the file sets A ₁₁ , A _1n , A ₃₁ , and A _3n in the matrix are inconsistent with the content of the certificate.

Further, comparing the calculated check codes corresponding to the multiple file sets with the check codes obtained from the blockchain network to obtain a comparison result, which may specifically include: of the file sets in the i-th line, obtain the line check codes corresponding to the i-th line of the file sets from the blockchain network; Comparing the line check codes corresponding to the plurality of the file sets with the line check codes corresponding to the plurality of the file sets of the i-th row obtained from the blockchain to obtain a line check code comparison Result: for the plurality of file sets in the jth column of the matrix, obtain the column check codes corresponding to the jth column of the file sets from the blockchain network; calculate the result The column check codes corresponding to the plurality of the document sets in the jth column are compared with the column check codes corresponding to the plurality of the document sets in the jth column obtained from the blockchain, Get the column check code comparison result.

It should be noted that after the check codes of each row of the matrix are compared and the check codes of each column of the matrix are compared, the specific tampered data can be determined, for example, by comparing the row check codes It is determined that the check codes in the third row in the matrix are inconsistent. By comparing the column check codes, it is determined that the check codes in the second column are inconsistent, and it can be determined that the data at the third row and the second column in the matrix has been tampered with. .

Optionally, if the algorithm used in the calculation of the check code is an erasure algorithm, part of the modified data can be recovered through the check code. For example, when using the RS algorithm, take N(Data Shards)=50 and Parity Shards=2, then, when the number of modified file sets in a row or column is less than or equal to 2; according to other values of the row or column and Check code, the set of files modified in the row or column can be recovered through the RS algorithm.

The technical effects that can be achieved by the above two embodiments are as follows: 1) In the scheme of storing the certificate on the chain of the large file Hash, the verifier cannot know which part of the file has been tampered with, and can only obtain whether the entire file is consistent with the original one. Final result. The technical solutions of the embodiments of this specification can independently verify each file set of a single large file, and use a controllable storage cost to determine which file sets in the large file have been modified and which are original content. In this way, during verification, the contents of the modified file collection can be directly found, and other contents can still be proved that they have not been tampered with.

2) Since the Hash on-chain deposit certificate does not store the original file, the source file is hosted and stored in an external system. There is a very small probability that the external system may cause partial damage to the file. For example, when using disk storage, the magnetic poles are reversed, causing data errors, or bad sectors causing data loss. The solutions in the embodiments of this specification can still provide proof of non-tampering for the correct or non-lost part; further, when the tampered data or the lost data accounts for a small part of the sorted data, the lost data can be verified through the certificate information. or tampered data to restore.

Based on the same idea, the embodiments of the present specification also provide a device corresponding to the above method. FIG. 8 is a schematic structural diagram of a file certificate storage device according to an embodiment of the present specification. As shown in FIG. 8 , the device may include: a target file acquisition module 810 for acquiring a target file to be stored; a file data determination module 820 for splitting the target file according to a preset splitting method, Obtaining the split multiple file data; a file set dividing module 830, configured to divide the multiple file data into multiple file sets according to a preset division method; each of the file sets contains m elements; verifying The code calculation module 840 is used to calculate the check codes corresponding to the multiple file sets; the location file data information determination module 850 is used to determine the location file data information in each of the file sets; the location file data information Including the location information of the location file data in the file set in the target file and the content information of the location file data; the data storage module 860 is used to store the check code and the location file data information. into the blockchain network.

Based on the device in FIG. 8 , some specific implementations of the method are also provided in the embodiments of this specification, which will be described below.

Optionally, the apparatus may further include: a digest value calculation module for calculating the digest value of the target file by using a hash algorithm; a digest value storage module for storing the digest value in the block in the chain network.

Optionally, the data storage module 860 may specifically include: a storage certificate data determination unit, configured to splicing the digest value, the check code and the positioning file data information according to a preset splicing method, Obtain the certificate data corresponding to the target file; the certificate data storage unit is used to store the certificate data in the blockchain network.

Optionally, the storage unit for the storage data may be specifically configured to: generate a certificate of storage including authentication information based on the storage data; send the storage data including the certificate of storage to the block storage in the chain network.

Optionally, the file set dividing module 830 may specifically include: a dividing unit, configured to divide the multiple file data into N file sets according to the preset number of files in the file set; The elements in the collection have order between them.

Optionally, the apparatus may further include: a file set arrangement module, configured to arrange the N file sets in the form of a matrix to obtain a matrix with N rows and M columns; the check code calculation module, specifically It includes: a check code calculation unit, configured to use an erasure correction algorithm to generate a corresponding check code for each row of the matrix corresponding to the multiple file sets; for each column of the file set of the matrix corresponding to the multiple file sets Generate the corresponding check code.

Optionally, the positioning file data information determining module 850 may specifically include: a positioning file data information determining unit, configured to determine an element at a specific position in each group of the file sets as positioning file data to obtain a positioning file. data collection.

Based on the same idea, the embodiments of the present specification also provide a device corresponding to the above method. FIG. 9 is a schematic structural diagram of a file verification apparatus according to an embodiment of the present specification. As shown in FIG. 9 , the device may include: a data acquisition module 910 for acquiring the location file data information and check code corresponding to the file to be verified from the blockchain network; the check code is obtained by The multiple file sets corresponding to the target file of the obtained by dividing the multiple file data; the positioning file data information includes the position information of the positioning file data in the file set in the target file and the content information of the positioning file data; the file set determining module 920 , for determining multiple file sets corresponding to the files to be verified based on the positioning file data information; a check code calculation module 930 for calculating the check codes corresponding to the multiple file sets; a comparison module 940 , for comparing the calculated check codes corresponding to the multiple file sets with the check codes obtained from the blockchain network to obtain a comparison result; the verification module 950 is used for Comparing the results, the document to be verified is verified.

Based on the device in FIG. 9 , some specific implementations of the method are also provided in the embodiments of this specification, which will be described below.

Optionally, the data acquisition module 910 may specifically include: an identification information acquisition unit for acquiring identification information corresponding to the to-be-verified file; a data acquisition unit for obtaining an identification information from the blockchain based on the identification information. The positioning file data information and the check code corresponding to the file to be verified are obtained from the network.

Optionally, the device may further include: a digest value calculation module, used for calculating the digest value of the to-be-verified file by using the Hash algorithm used when storing the certificate; a digest value comparison module, used for calculating the calculated digest value. The digest value of the document to be verified is compared with the digest value in the certificate data; the tampering situation determination unit is used to calculate the digest value of the document to be verified and the digest in the certificate data. When the values are consistent, it is determined that the file to be verified has not been tampered with; when the calculated digest value of the to-be-verified file is inconsistent with the digest value in the certificate data, based on the location file data information, it is determined that the Multiple file sets corresponding to the files to be verified.

Optionally, the file set determining module 920 may specifically include: a first positioning file data set determining unit, configured to determine a first positioning file data set based on the location information; a second positioning file data set determining unit, Based on a dynamic programming algorithm, determine a second positioning file data set whose coverage meets a preset condition from the first positioning file set; a positioning file data information comparison unit is used to compare the second positioning file data set with the The pre-stored positioning file data information is compared to determine inconsistent positioning file data information; the third positioning file data set determining unit is used to determine the third positioning file data set according to the inconsistent positioning file data information, so that the The matching rate between the third positioning file data set and the pre-stored positioning file data is the largest; the file set determining unit is configured to determine, based on the third positioning file data set, multiple file sets corresponding to the to-be-verified file.

Optionally, the check code calculation module 930 may specifically include: a file set arrangement unit for arranging the N file sets in the form of a matrix to obtain a matrix with N rows and M columns; check code generation The unit is configured to use an erasure correction algorithm to generate corresponding row check codes for the multiple file sets corresponding to each row of the matrix; generate the corresponding multiple file sets corresponding to each column of the matrix. Column check code.

Optionally, the comparison module 940 may be specifically configured to: for a plurality of the file sets in the i-th row in the matrix, obtain a plurality of the i-th row from the blockchain network The line check code corresponding to the file set; compare the calculated line check code corresponding to the i-th line of the file set with the i-th line obtained from the blockchain. The row check codes corresponding to the file sets are compared to obtain a row check code comparison result; for the plurality of the document sets in the jth column of the matrix, all the file sets are obtained from the blockchain network. The column check codes corresponding to the plurality of the document sets in the jth column; the calculated column check codes corresponding to the plurality of the document sets in the jth column and the obtained from the blockchain. The column check codes corresponding to the plurality of the document sets in the jth column are compared to obtain a column check code comparison result.

Based on the same idea, the embodiments of this specification also provide a device corresponding to the above method.

FIG. 10 is a schematic diagram of a document storage and verification device provided by an embodiment of the present specification. As shown in FIG. 10 , the device 1000 may include: at least one processor 1010 ; and a memory 1030 communicatively connected to the at least one processor; wherein the memory 1030 stores information executable by the at least one processor 1010 corresponding to Embodiment 1, the instruction 1020 is executed by the at least one processor 1010, so that the at least one processor 1010 can: obtain the target file to be stored; The target file is split to obtain multiple split file data; the multiple file data is divided into multiple file sets according to a preset division method; each of the file sets contains m elements; the corresponding check codes of the multiple file sets; determine the location file data information in each of the file sets; the location file data information includes the location information of the location file data in the file set in the target file. and the content information of the positioning file data; the check code and the positioning file data information are stored in the blockchain network.

Corresponding to Embodiment 2, the instruction 1020 is executed by the at least one processor 1010, so that the at least one processor 1010 can: obtain the location file data information corresponding to the to-be-verified file and verify it from the blockchain network The check code is obtained by calculating multiple file sets corresponding to the pre-stored target file; the multiple file sets are splitting the target file according to the preset splitting method to obtain A plurality of file data is obtained by dividing the plurality of file data according to a preset division method; the location file data information includes the location information of the location file data in the file set in the target file and the location information of the target file. the content information of the location file data; based on the location file data information, determine multiple file sets corresponding to the to-be-verified file; calculate the check codes corresponding to the multiple file sets; The check code corresponding to the file set is compared with the check code obtained from the blockchain network to obtain a comparison result; based on the comparison result, the to-be-verified file is verified.

Based on the same idea, the embodiments of the present specification also provide a computer-readable medium corresponding to the above method. Computer-readable instructions are stored on the computer-readable medium, corresponding to Embodiment 1, and the computer-readable instructions can be executed by the processor to implement the following methods: acquiring the target file to be stored; splitting the target file to obtain multiple file data after splitting; dividing the multiple file data into multiple file sets according to a preset division method; each of the file sets contains m elements; calculating the Check codes corresponding to multiple file sets; determine the location file data information in each of the file sets; the location file data information includes location information of the location file data in the file set in the target file and The content information of the positioning file data; the check code and the positioning file data information are stored in the blockchain network.

Corresponding to Embodiment 2, the computer-readable instructions can be executed by the processor to implement the following method: obtain the location file data information and check code corresponding to the file to be verified from the blockchain network; the check code is obtained by It is obtained by calculating multiple file sets corresponding to the pre-stored target file; the multiple file sets are obtained by splitting the target file according to the preset splitting method to obtain multiple file data, and the multiple file sets are divided according to the preset method. The division method is obtained by dividing the plurality of file data; the location file data information includes the location information of the location file data in the file set in the target file and the content information of the location file data; based on Locating the file data information, determining multiple file sets corresponding to the to-be-verified file; calculating the check codes corresponding to the multiple file sets; comparing the calculated check codes corresponding to the multiple file sets with the The verification codes obtained in the blockchain network are compared to obtain a comparison result; based on the comparison result, the to-be-verified file is verified.

The various embodiments in this specification are described in a progressive manner, and the same and similar parts between the various embodiments may be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the device embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and reference may be made to the partial descriptions of the method embodiments for related parts.

In the 1990s, improvements in a technology could be clearly differentiated between improvements in hardware (eg, improvements to circuit structures such as diodes, transistors, switches, etc.) or improvements in software (improvements in method flow). However, with the development of technology, the improvement of many methods and processes today can be regarded as a direct improvement of the hardware circuit structure. Designers almost get the corresponding hardware circuit structure by programming the improved method flow into the hardware circuit. Therefore, it cannot be said that the improvement of a method flow cannot be realized by hardware entity modules. For example, a Programmable Logic Device (PLD) (such as a Field Programmable Gate Array (FPGA)) is an integrated circuit whose logic function is determined by user programming of the device. It is programmed by the designer to "integrate" a digital character system on a PLD, without the need for a chip manufacturer to design and manufacture a dedicated integrated circuit chip. Moreover, today, instead of making integrated circuit chips by hand, this kind of programming is also mostly implemented using "logic compiler" software, which is similar to the software compiler used in program development and writing, and needs to be compiled before compiling. The original code also has to be written in a specific programming language, which is called Hardware Description Language (HDL), and there is not only one HDL, but many kinds, such as ABEL (Advanced Boolean Expression Language) , AHDL (Altera Hardware Description Language), Confluence, CUPL (Cornell University Programming Language), HDCal, JHDL (Java Hardware Description Language), Lava, Lola, MyHDL, PALASM, RHDL (Ruby Hardware Description Language), etc., currently the most commonly used The ones are VHDL (Very-High-Speed Integrated Circuit Hardware Description Language) and Verilog. It should also be clear to those skilled in the art that a hardware circuit for implementing the logic method process can be easily obtained by simply programming the method process in the above-mentioned several hardware description languages and programming it into the integrated circuit.

The controller may be implemented in any suitable manner, for example, the controller may take the form of eg a microprocessor or processor and a computer readable medium storing computer readable program code (eg software or firmware) executable by the (micro)processor , logic gates, switches, application specific integrated circuits (ASICs), programmable logic controllers and embedded microcontrollers, examples of controllers include but are not limited to the following microcontrollers: ARC 625D, Atmel AT91SAM, Microchip PIC18F26K20 and Silicon Labs C8051F320, the memory controller can also be implemented as part of the control logic of the memory. Those skilled in the art also know that, in addition to implementing the controller in the form of pure computer-readable program code, the controller can be implemented as logic gates, switches, application-specific integrated circuits, programmable logic controllers and embedded devices by logically programming the method steps. The same function can be realized in the form of a microcontroller, etc. Therefore, this kind of controller can be regarded as a hardware component, and the devices included therein for realizing various functions can also be regarded as a structure in the hardware component. Or even, the means for implementing various functions can be regarded as both a software module implementing a method and a structure within a hardware component.

The systems, devices, modules or units described in the above embodiments may be specifically implemented by computer chips or entities, or by products with certain functions. A typical implementation device is a computer. Specifically, the computer may be, for example, a personal computer, a laptop computer, a cellular phone, a camera phone, a smart phone, a personal digital assistant, a media player, a navigation device, an email device, a game console, a tablet computer, a wearable device Or a combination of any of these devices.

For the convenience of description, when describing the above device, the functions are divided into various units and described respectively. Of course, when implementing the present application, the functions of each unit may be implemented in one or more software and/or hardware.

As will be appreciated by one skilled in the art, embodiments of the present invention may be provided as a method, system, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention may 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.) having computer-usable program code embodied therein.

The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each process and/or block in the flowchart illustrations and/or block diagrams, and combinations of processes and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to the processor of a general purpose computer, special purpose computer, embedded processor or other programmable data processing device to produce a machine such that the instructions executed by the processor of the computer or other programmable data processing device produce Means for implementing the functions specified in a flow or flow of a flowchart and/or a block or blocks of a block diagram.

These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory result in an article of manufacture comprising instruction means, the instructions The apparatus implements the functions specified in the flow or flow of the flowcharts and/or the block or blocks of the block diagrams.

These computer program instructions can also be loaded on a computer or other programmable data processing device to cause a series of operational steps to be performed on the computer or other programmable device to produce a computer-implemented process such that The instructions provide steps for implementing the functions specified in the flow or blocks of the flowcharts and/or the block or blocks of the block diagrams.

In a typical configuration, a computing device includes one or more processors (CPUs), input/output interfaces, network interfaces, and memory.

Memory may include forms of non-persistent memory, random access memory (RAM) and/or non-volatile memory in computer readable media, such as read only memory (ROM) or flash memory (flash RAM). Memory is an example of a computer-readable medium.

Computer readable media includes both persistent and non-permanent, removable and non-removable media and can be implemented by any method or technology for storage of information. Information may be computer readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read only memory (ROM), Electrically Erasable Programmable Read Only Memory (EEPROM), Flash Memory or other memory technology, Compact Disc Read Only Memory (CD-ROM), Digital Versatile Disc (DVD), or other optical storage , magnetic tape cartridges, magnetic tape-disk storage or other magnetic storage devices or any other non-transmission medium that can be used to store information that can be accessed by a computing device. As defined herein, computer-readable media does not include transitory computer-readable media, such as modulated data signals and carrier waves.

It should also be noted that the terms "comprising", "comprising" or any other variation thereof are intended to encompass a non-exclusive inclusion such that a process, method, article or device comprising a series of elements includes not only those elements, but also Other elements not expressly listed, or which are inherent to such a process, method, article of manufacture, or apparatus are also included. Without further limitation, an element qualified by the phrase "comprising a..." does not preclude the presence of additional identical elements in the process, method, article of manufacture, or device that includes the element.

It will be appreciated by those skilled in the art that the embodiments of the present application may be provided as a method, a system or a computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present application may 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.) having computer-usable program code embodied therein.

The application may be described in the general context of computer-executable instructions, such as program modules, being executed by a computer. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types. The application may also be practiced in distributed computing environments where tasks are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, program modules may be located in both local and remote computer storage media including storage devices.

The above descriptions are merely examples of the present application, and are not intended to limit the present application. Various modifications and variations of this application are possible for those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the scope of the claims of the present application.

Claims

A method of document preservation, including:

Obtain the target file to be stored;

Splitting the target file according to a preset splitting method to obtain multiple split file data;

Divide the multiple file data into multiple file sets according to a preset division method; each of the file sets includes m elements;

calculating the check codes corresponding to the multiple file sets;

Determine the positioning file data information in each of the file sets; the positioning file data information includes the position information of the positioning file data in the file set in the target file and the content information of the positioning file data;

The check code and the positioning file data information are stored in the blockchain network.
The method of claim 1, further comprising:

adopt a hash algorithm to calculate the digest value of the target file;

The digest value is stored in the blockchain network.
The method according to claim 2, wherein storing the check code and the positioning file data information in a blockchain network specifically includes:

According to a preset splicing method, splicing the digest value, the check code and the positioning file data information to obtain the certificate data corresponding to the target file;

The depository data is stored in the blockchain network.
The method according to claim 3, the storing the certificate data in the blockchain network specifically includes:

Based on the deposit data, generating a deposit certificate containing authentication information;

Send the deposit data including the deposit certificate to the blockchain network for storage.
The method according to claim 1, wherein the dividing the plurality of file data into a plurality of file sets according to a preset dividing manner specifically includes:

According to the preset number of files in the file set, the plurality of file data is divided into N file sets; the elements in each of the file sets have an order.
The method according to claim 5, before calculating the check codes corresponding to the multiple file sets, further comprising:

Arrange the N document sets in the form of a matrix to obtain a matrix of N rows and M columns;

The calculating the check codes corresponding to the multiple file sets specifically includes:

Using an erasure correction algorithm, a corresponding check code is generated for each row of the matrix corresponding to the multiple file sets; and a corresponding check code is generated for each column file set of the matrix corresponding to the multiple file sets.
The method according to claim 1, wherein the determining of the location file data information in each of the file sets specifically includes:

Elements at specific positions in each group of the file sets are determined as positioning file data to obtain a positioning file data set.
A method of document verification, including:

Obtain the positioning file data information and check code corresponding to the file to be verified from the blockchain network; the check code is obtained by calculating multiple file sets corresponding to the pre-stored target file; the multiple The file set is obtained by splitting the target file according to a preset splitting method to obtain multiple file data, and dividing the multiple file data according to the preset splitting method; the location file data information includes all the file data. the location information of the location file data in the described file set in the target file and the content information of the location file data;

Determine, based on the location file data information, multiple file sets corresponding to the to-be-verified file;

calculating the check codes corresponding to the multiple file sets;

Comparing the calculated check codes corresponding to the multiple file sets with the check codes obtained from the blockchain network to obtain a comparison result;

Based on the comparison result, the to-be-verified file is verified.
The method according to claim 8, the obtaining from the blockchain network the positioning file data information and the check code corresponding to the file to be verified, specifically includes:

obtaining the identification information corresponding to the document to be verified;

Based on the identification information, the positioning file data information and the check code corresponding to the to-be-verified file are obtained from the blockchain network.
The method according to claim 8, before determining, based on the locating file data information, multiple file sets corresponding to the to-be-verified file, further comprising:

Calculate the digest value of the document to be verified by using the Hash algorithm used when depositing the certificate;

Comparing the calculated digest value of the document to be verified with the digest value in the certificate data;

When the calculated digest value of the to-be-verified file is consistent with the digest value in the certificate data, it is determined that the to-be-verified file has not been tampered with;

When the calculated digest value of the to-be-verified file is inconsistent with the digest value in the certificate storage data, multiple file sets corresponding to the to-be-verified file are determined based on the location file data information.
The method according to claim 8, wherein the determining of multiple file sets corresponding to the to-be-verified file based on the positioning file data information specifically includes:

determining a first positioning file data set based on the location information;

Based on a dynamic programming algorithm, determine a second location file data set whose coverage meets a preset condition from the first location file set;

Comparing the second positioning file data set with pre-stored positioning file data information to determine inconsistent positioning file data information;

According to the inconsistent positioning file data information, determine a third positioning file data set, so that the matching rate between the third positioning file data set and the pre-stored positioning file data is maximized;

Based on the third location file data set, multiple file sets corresponding to the to-be-verified file are determined.
The method according to claim 11, wherein the calculating the check codes corresponding to the multiple file sets specifically includes:

Arrange the N document sets in the form of a matrix to obtain a matrix of N rows and M columns;

Erasure erasure algorithm is used to generate corresponding row check codes for multiple file sets corresponding to each row of the matrix; and corresponding column check codes are generated for multiple file sets corresponding to each column of the matrix .
The method according to claim 12, comparing the calculated check codes corresponding to the multiple file sets with the check codes obtained from the blockchain network to obtain a comparison result, which specifically includes:

For a plurality of the file sets in the i-th row of the matrix, obtain row check codes corresponding to the i-th row of the file sets from the blockchain network;

Perform the calculation of the line check codes corresponding to the plurality of the file sets in the i-th row obtained from the calculation with the line check codes corresponding to the file sets in the i-th line obtained from the blockchain. Compare, get the row check code comparison result;

For a plurality of the document sets in the jth column of the matrix, obtain from the blockchain network the column check codes corresponding to the jth column of the document sets;

The calculated column check codes corresponding to the plurality of the document sets in the jth column are performed with the column check codes corresponding to the plurality of the document sets in the jth column obtained from the blockchain. Compare, get the column check code comparison result.
A document storage device, comprising:

The target file acquisition module is used to obtain the target file to be stored;

a file data determination module, configured to split the target file according to a preset splitting method to obtain multiple split file data;

a file set division module, configured to divide the multiple file data into multiple file sets according to a preset division method; each of the file sets contains m elements;

a check code calculation module, configured to calculate the check codes corresponding to the multiple file sets;

The positioning file data information determination module is used to determine the positioning file data information in each of the file sets; the positioning file data information includes the position information of the positioning file data in the file set in the target file and all Describe the content information of the location file data;

The data storage module is used for storing the check code and the data information of the positioning file in the blockchain network.
The device according to claim 14, wherein the file set dividing module specifically comprises:

The dividing unit is configured to divide the plurality of file data into N file sets according to the preset number of files in the file set; elements in each of the file sets have an order.
The apparatus of claim 15, the apparatus further comprising:

a file set arrangement module, used for arranging the N described file sets in the form of a matrix to obtain a matrix of N rows and M columns;

The verification code calculation module specifically includes:

A check code calculation unit, configured to use an erasure correction algorithm to generate a corresponding check code for each row of the matrix corresponding to the multiple file sets; generate a corresponding check code for each column of the file set of the matrix corresponding to the multiple file sets check code.
A document verification device, comprising:

The data acquisition module is used to acquire the positioning file data information and the check code corresponding to the file to be verified from the blockchain network; the check code is obtained by calculating multiple file sets corresponding to the pre-certified target file The multiple file sets are obtained by splitting the target file according to a preset splitting method to obtain multiple file data, and dividing the multiple file data according to a preset splitting method; the The location file data information includes location information of the location file data in the file set in the target file and content information of the location file data;

a file set determining module, configured to determine a plurality of file sets corresponding to the to-be-verified file based on the positioning file data information;

a check code calculation module, configured to calculate the check codes corresponding to the multiple file sets;

A comparison module, configured to compare the calculated check codes corresponding to the multiple file sets with the check codes obtained from the blockchain network to obtain a comparison result;

A verification module, configured to verify the to-be-verified file based on the comparison result.
The apparatus of claim 17, the apparatus further comprising:

The digest value calculation module is used to calculate the digest value of the to-be-verified file by using the Hash algorithm used when storing the certificate;

The digest value comparison module is configured to compare the calculated digest value of the document to be verified with the digest value in the certificate data;

A tampering situation determination unit, configured to determine that the to-be-verified file has not been tampered with when the calculated digest value of the to-be-verified file is consistent with the digest value in the certificate data; When the digest value of the file is inconsistent with the digest value in the certification data, multiple file sets corresponding to the to-be-verified file are determined based on the location file data information.
The apparatus according to claim 17, the file set determination module, specifically comprising:

a first positioning file data set determining unit, configured to determine a first positioning file data set based on the location information;

A second positioning file data set determining unit, configured to determine, based on a dynamic programming algorithm, a second positioning file data set whose coverage satisfies a preset condition from the first positioning file set;

a positioning file data information comparison unit, configured to compare the second positioning file data set with pre-stored positioning file data information, and determine inconsistent positioning file data information;

A third positioning file data set determining unit, configured to determine a third positioning file data set according to the inconsistent positioning file data information, so as to maximize the matching rate between the third positioning file data set and the pre-stored positioning file data ;

A file set determination unit, configured to determine, based on the third located file data set, multiple file sets corresponding to the to-be-verified file.
The device according to claim 19, the check code calculation module specifically comprises:

a file set arrangement unit, used for arranging the N described file sets in the form of a matrix to obtain a matrix of N rows and M columns;

A check code generation unit, configured to use an erasure correction algorithm to generate a corresponding row check code for a plurality of the file sets corresponding to each row of the matrix; for a plurality of the files corresponding to each column of the matrix The set generates the corresponding column check code.
The device according to claim 20, the comparison module is specifically used for:

For a plurality of the file sets in the i-th row of the matrix, obtain row check codes corresponding to the i-th row of the file sets from the blockchain network;

Perform the calculation of the line check codes corresponding to the plurality of the file sets in the i-th row obtained from the calculation with the line check codes corresponding to the file sets in the i-th line obtained from the blockchain. Compare, get the row check code comparison result;

For a plurality of the document sets in the jth column of the matrix, obtain from the blockchain network the column check codes corresponding to the jth column of the document sets;

The calculated column check codes corresponding to the plurality of the document sets in the jth column are performed with the column check codes corresponding to the plurality of the document sets in the jth column obtained from the blockchain. Compare, get the column check code comparison result.
A document storage device, comprising:

at least one processor; and,

a memory communicatively coupled to the at least one processor; wherein,

The memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to:

obtaining the target file to be stored; splitting the target file according to a preset splitting method to obtain multiple split file data;

Divide the multiple file data into multiple file sets according to a preset division method; each of the file sets includes m elements;

calculating the check codes corresponding to the multiple file sets;

Determine the positioning file data information in each of the file sets; the positioning file data information includes the position information of the positioning file data in the file set in the target file and the content information of the positioning file data;

The check code and the positioning file data information are stored in the blockchain network.
A document verification device comprising:

at least one processor; and,

a memory communicatively coupled to the at least one processor; wherein,

The memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to:

Obtain the positioning file data information and check code corresponding to the file to be verified from the blockchain network; the check code is obtained by calculating multiple file sets corresponding to the pre-stored target file; the multiple The file set is obtained by splitting the target file according to a preset splitting method to obtain multiple file data, and dividing the multiple file data according to the preset splitting method; the location file data information includes all the file data. the location information of the location file data in the described file set in the target file and the content information of the location file data;

Determine, based on the location file data information, multiple file sets corresponding to the to-be-verified file;

calculating the check codes corresponding to the multiple file sets;

Comparing the calculated check codes corresponding to the multiple file sets with the check codes obtained from the blockchain network to obtain a comparison result;

Based on the comparison result, the to-be-verified file is verified.
A computer readable medium having stored thereon computer readable instructions executable by a processor to implement the method of any one of claims 1 to 13.