CN116579025A

CN116579025A - File storage method, device and equipment

Info

Publication number: CN116579025A
Application number: CN202310530555.6A
Authority: CN
Inventors: 印明亮; 余珊; 王凯
Original assignee: Alipay Hangzhou Information Technology Co Ltd; Ant Blockchain Technology Shanghai Co Ltd
Current assignee: Alipay Hangzhou Information Technology Co Ltd; Ant Blockchain Technology Shanghai Co Ltd
Priority date: 2021-04-20
Filing date: 2021-04-20
Publication date: 2023-08-11
Also published as: CN113065169A; CN113065169B; WO2022222786A1

Abstract

The embodiment of the specification discloses a method, a device and equipment for document storage, wherein the method comprises the following steps: obtaining a target file to be stored; splitting the target file according to a preset splitting mode to obtain a plurality of split file data; dividing the plurality of file data into a plurality of file sets according to a preset dividing mode; and calculating check codes corresponding to the file sets, determining positioning file data information in each file set, and storing the check codes and the positioning file data information into a block chain network.

Description

File storage method, device and equipment

Technical Field

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

Background

Blockchain (Blockchain) is a new application mode of computer technologies such as distributed data storage, point-to-point transmission, consensus mechanisms, encryption algorithms, and the like. In the block chain system, the data blocks are combined into a chain data structure in a sequential connection mode according to the time sequence, and the distributed account book which is not tamperable and counterfeit and is ensured in a cryptographic mode is formed. It is essentially a decentralized distributed database system with participation of nodes. Because the blockchain has the characteristics of decentralization, non-falsification of information, autonomy and the like, the adoption of the blockchain to store the document data is also receiving more and more attention and application from people.

Disclosure of Invention

The embodiment of the specification provides a file storage method, a device and equipment, which are used for solving the problem that tampered data in a file are difficult to locate in the existing file storage and verification methods.

In order to solve the above technical problems, the embodiments of the present specification are implemented as follows:

the method for storing and verifying the file provided by the embodiment of the specification comprises the following steps:

obtaining a target file to be stored;

splitting the target file according to a preset splitting mode to obtain a plurality of split file data;

dividing the plurality of file data into a plurality of file sets according to a preset dividing mode; each file set comprises m elements;

calculating check codes corresponding to the plurality of file sets;

determining positioning file data information in each file set; the positioning file data information comprises the position information of positioning file data in the file set in the target file and the content information of the positioning file data;

and storing the check code and the positioning file data information into a block chain network.

The file verification method provided by the embodiment of the specification comprises the following steps:

Acquiring positioning file data information and check codes corresponding to a file to be verified from a block chain network; the check code is obtained by calculating a plurality of file sets corresponding to the pre-stored target files; the plurality of file sets are obtained by splitting the target file according to a preset splitting mode to obtain a plurality of file data and dividing the plurality of file data according to a preset dividing mode; the positioning file data information comprises the position information of positioning file data in the file set in the target file and the content information of the positioning file data;

determining a plurality of file sets corresponding to the files to be verified based on the positioning file data information;

calculating check codes corresponding to the plurality of file sets;

comparing the calculated check codes corresponding to the plurality of file sets with the check codes obtained from the blockchain network to obtain a comparison result;

and verifying the file to be verified based on the comparison result.

The embodiment of the specification provides a document evidence-preserving device, including:

the target file acquisition module is used for acquiring a target file to be stored;

The file data determining module is used for splitting the target file according to a preset splitting mode to obtain a plurality of split file data;

the file set dividing module is used for dividing the plurality of file data into a plurality of file sets according to a preset dividing mode; each file set comprises m elements;

the check code calculation module is used for calculating check codes corresponding to the plurality of file sets;

the positioning file data information determining module is used for determining positioning file data information in each file set; the positioning file data information comprises the position information of positioning file data in the file set in the target file and the content information of the positioning file data;

and the data storage module is used for storing the check code and the positioning file data information into a blockchain network.

The embodiment of the present specification provides a document verification device, including:

the data acquisition module is used for acquiring positioning file data information and check codes corresponding to the files to be verified from the blockchain network; the check code is obtained by calculating a plurality of file sets corresponding to the pre-stored target files; the plurality of file sets are obtained by splitting the target file according to a preset splitting mode to obtain a plurality of file data and dividing the plurality of file data according to a preset dividing mode; the positioning file data information comprises the position information of 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 is used for determining a plurality of file sets corresponding to the files to be verified based on the positioning file data information;

the comparison module is used for comparing the calculated check codes corresponding to the plurality of file sets with the check codes obtained from the blockchain network to obtain a comparison result;

and the verification module is used for verifying the file to be verified based on the comparison result.

The embodiment of the specification provides a document evidence-preserving device, which comprises:

at least one processor; the method comprises the steps of,

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

the memory stores instructions executable by the at least one processor to enable the at least one processor to:

obtaining a target file to be stored; splitting the target file according to a preset splitting mode to obtain a plurality of split file data;

Calculating check codes corresponding to the plurality of file sets;

The embodiment of the specification provides a file verification device, which comprises:

at least one processor; the method comprises the steps of,

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

calculating check codes corresponding to the plurality of file sets;

and verifying the file to be verified based on the comparison result.

Embodiments of the present disclosure provide a computer readable medium having computer readable instructions stored thereon, the computer readable instructions being executable by a processor to implement a method of document authentication.

One embodiment of the present specification achieves the following advantageous effects: obtaining a target file to be stored; splitting the target file according to a preset splitting mode to obtain a plurality of split file data; dividing the plurality of file data into a plurality of file sets according to a preset dividing mode; and calculating check codes corresponding to the file sets, determining positioning file data information in each file set, and storing the check codes and the positioning file data information into a block chain network. By the method for storing the evidence on the large file chain, all data corresponding to the target file is not required to be stored in the blockchain network, and the defect of data expansion is avoided. And introducing a check code and positioning file data information, and positioning tampered data in the target file when the stored target file is tampered.

Drawings

In order to more clearly illustrate the embodiments of the present description or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described below, it being obvious that the drawings in the following description are only some embodiments described in the present application, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic diagram of an application scenario of a document authentication method in an embodiment of the present disclosure;

fig. 2 is a flow chart of a document authentication method according to an embodiment of the present disclosure;

FIG. 3 is a schematic diagram of an arrangement of file sets according to an embodiment of the present disclosure;

fig. 4 is a flow chart of a document authentication method according to an embodiment of the present disclosure;

fig. 5 is a schematic diagram of preliminary positioning based on positioning file data information according to an embodiment of the present disclosure;

FIG. 6 is a schematic diagram of performing supplemental positioning based on positioning file data information according to an embodiment of the present disclosure;

FIG. 7 is a schematic diagram of verification based on a check code according to an embodiment of the present disclosure;

fig. 8 is a schematic structural diagram of a document storage device according to an embodiment of the present disclosure;

Fig. 9 is a schematic structural diagram of a document verification device according to an embodiment of the present disclosure;

fig. 10 is a schematic diagram of a document authentication and verification device according to an embodiment of the present disclosure.

Detailed Description

For the purposes of making the objects, technical solutions and advantages of one or more embodiments of the present specification more clear, the technical solutions of one or more embodiments of the present specification will be clearly and completely described below in connection with specific embodiments of the present specification and corresponding drawings. It will be apparent that the described embodiments are only some, but not all, of the embodiments of the present specification. All other embodiments, which can be made by one of ordinary skill in the art based on the embodiments herein without undue burden, are intended to be within the scope of one or more embodiments herein.

The following describes in detail the technical solutions provided by the embodiments of the present specification with reference to the accompanying drawings.

In the embodiments of the present specification, the terms involved are explained as follows:

blockchain (Block chain): the "blockchain" technology is a special distributed database technology designed by the artificial bit coin of the present intelligence in a bit name, which can be understood as a data chain formed by sequentially storing a plurality of blocks, wherein the block head of each block comprises the timestamp of the present block, the hash value of the previous block information and the hash value of the present block information, thereby realizing the mutual verification between the blocks and forming the tamper-proof blockchain. Each block is understood to be a block of data (a unit of stored data). The block chain is used as a decentralization database and is a series of data blocks which are generated by mutually correlating a cryptography method, and each data block contains information of one network transaction and is used for verifying the validity (anti-counterfeiting) of the information and generating a next block. The chain formed by connecting blocks end to end is the block chain. If the data in the block needs to be modified, the contents of all blocks after the block need to be modified, and the data backed up by all nodes in the blockchain network are modified. Therefore, the blockchain is characterized by being difficult to tamper with and delete, and has reliability as a method for maintaining the integrity of the content after the data has been saved to the blockchain.

Hash algorithm: an arbitrary length input (also called pre-mapped pre-image) is transformed by a hashing algorithm into a fixed length output, which is the hash value. This conversion is a compressed mapping, the hash value is typically much smaller in space than the input, different inputs may be hashed to the same output, so it is not possible to determine a unique input value from the hash value. May be a function of a message digest that compresses messages of arbitrary length to a certain fixed length. SHA256, SM3 algorithms are more common.

Erasure algorithm: the basic principle is to segment the transmitted signal, add a certain check and then let a certain link between the segments, even if part of the signal is lost in the transmission process, the receiving end can still calculate the complete information through the algorithm. For example: error correction code algorithm (Reed-solomon, abbreviated RS algorithm).

Because of the nature of the blockchain distributed ledger, each participant will have at least one piece of ledger data. In the existing file verification scheme based on the blockchain, the file data is generally recorded on the blockchain directly, and is directly verified through the blockchain. The adoption of the mode that the file is directly connected with the uplink can generate the problem of data expansion, because the size of the file can be strictly limited due to the limitation of the transaction size of the blockchain, the file is convenient to store, and potential safety hazards can also exist, so that the development of the blockchain technology is not facilitated.

On the other hand, some documents contain sensitive information, which is not suitable for storing in the form of a text directly on a chain. For large or sensitive files, a Hash chaining manner is generally adopted: before the uplink, a Hash value (abstract value) of the file is calculated through a certain Hash algorithm, and then the Hash value is uplink for verification. For example, using a Hash algorithm such as SHA256, pre-calculating SHA256 values of the file to be authenticated, and then chaining the SHA256 values of 32 bytes; this approach is irreversibly converted into a 32-byte digest no matter how large the source file is.

However, when the authenticity of the file is verified, the file to be verified is obtained from other systems, the Hash value of the file is calculated again and compared with the Hash value on the chain, when the Hash value is consistent, the file is not tampered, and when the Hash value is inconsistent, the file is tampered. In the scheme of large file Hash uplink, a Hash algorithm with enough strength, such as SHA256 algorithm, SM3 algorithm and the like, is generally required to be selected; algorithms that present safety hazards, such as: CRC, MD5, etc.

Fig. 1 is a schematic diagram of an application scenario of a document authentication and verification method in an embodiment of the present disclosure. As shown in fig. 1, for a target file X to be authenticated, the target file X is analyzed to obtain authentication data X1 corresponding to the target file, where the authentication data X1 may include a digest value, a check code, and information of positioning file data. The certification data X1 is stored in the blockchain network 110. The original data X2 corresponding to the target file X may be stored in the external device 120 outside the blockchain network, for example: a usb disk or other server.

Next, a document authentication method provided for the embodiments of the present disclosure will be specifically described with reference to the accompanying drawings:

example 1

Fig. 2 is a flow chart of a document authentication method according to an embodiment of the present disclosure. From the program perspective, the execution subject of the flow may be a program or an application client that is installed on an application server.

As shown in fig. 2, the process may include the steps of:

step 210: and obtaining the target file to be stored.

The blockchain data storage certificate can indicate that the data is stored on the blockchain, so that the purposes of tamper resistance, traceability and trusted data source are achieved. In order to realize quick transaction, in general, the link is used for cooperative work under the link, and the mode that the file is separated from the hash value is adopted, so that only the hash value of the file is stored on the link, and the original file is stored under the link. If the hash value of the file is calculated and compared with the hash value on the chain, whether the file is tampered is known. In the embodiment of the present disclosure, the data in the target file to be authenticated may be in any file form such as text, video, and audio. The whole file data corresponding to the target file is not required to be stored in the blockchain network, and only the corresponding data capable of representing the target file is required to be stored.

Step 220: splitting the target file according to a preset splitting mode to obtain a plurality of split file data.

It should be noted that, the resolution may be understood in a conventional sense: the different parts combined into one whole are separated separately into split. The middle split of this step can be understood as: dividing the data forming the target bit file into a plurality of file data according to the byte length corresponding to the fixed file data, for example: the target file has 100 bytes of corresponding data, and can be split into 100 file data according to a splitting mode of 1 byte of each small file data. Of course, it is also possible to use one file data or element every ten bytes, namely: the data corresponding to the 1 st to 10 th bytes are marked as first file data or first element, the data corresponding to the 11 th to 20 th bytes are marked as second file data or second element, … …, and so on, the target file is split into a plurality of file data or a plurality of elements. And splitting the obtained file data or elements for dividing the subsequent set.

Step 230: dividing the plurality of file data into a plurality of file sets according to a preset dividing mode; each file set contains m elements, and m is more than or equal to 1.

The preset dividing manner may represent the number of files contained in each preset file set, for example: the preset division mode is that 3 files are a file set.

After the target file is split into a plurality of file data or a plurality of elements, the plurality of files are divided into a plurality of file sets according to a preset division mode.

It should be noted that an element may represent one or more file data, and specifically, an element may be file data, for example: the target file X is split into X1, X2, X3, and X4, and when splitting, X1 and X2 are split into set 1, and X3 and X4 are split 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, in the case where the number of elements in each file set is set to be fixed, there may be a case where the number of elements in the last set is insufficient, in which case the elements missing in the set may be filled with fixed characters. Thus, the element may also be a fixed character, such as: \00.

Step 240: and calculating check codes corresponding to the plurality of file sets.

The check code may represent a piece of check data calculated on a certain length of original data by a certain algorithm (e.g., a Hash algorithm or an erasure algorithm). By checking the data, whether the new data is consistent with the original data can be judged, and the original data can be further calculated from the new data of which the original data is slightly modified.

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

Step 250: and determining positioning file data information in each file set.

Optionally, the determining the locating file data information in each file set may specifically include:

and determining the elements at the specific positions in each group of file sets as positioning file data to obtain a positioning file data set.

The location file data information may represent data information at a specific location in each file set, and more specifically, the location file data information may include location information of location file data in the file set in the target file and content information of the location file data. The location file data may also be referred to as a location code. Wherein the location code may be an element in the set of files, the element may be one or more file data; after the target file is divided into a plurality of file sets, the approximate location of the originally divided sets in the new data can be approximately determined by the location code. For example: the first element in each set may be used for the location code, assuming 9 elements in each set, from which it may be determined approximately that the next 9 elements may belong to a file set, starting from the data corresponding to the location code.

It should be noted that, in practical application, the positioning file data may be original data in the target file, or may be a value obtained by calculating the original data, for example: may be a hash value or a check value calculated on the data for positioning. Thus, when the positioning file data is stored in the blockchain network, only the calculated hash value or the check value is required to be stored.

Step 260: and storing the check code and the positioning file data information into a block chain network.

When the target file is authenticated, not all the data corresponding to the whole target file is stored in the blockchain network, and the original data is stored on a device outside the blockchain network, for example: may be stored in a mobile hard disk. The data to be verified in the blockchain network is a check code obtained by analyzing and calculating the target file and positioning file data information. The tampered data in the target file can be positioned through the check code and the positioning file data information.

It should be understood that the method according to one or more embodiments of the present disclosure may include the steps in which some of the steps are interchanged as needed, or some of the steps may be omitted or deleted.

The method in fig. 2 is implemented by acquiring a target file to be authenticated; splitting the target file according to a preset splitting mode to obtain a plurality of split file data; dividing the plurality of file data into a plurality of file sets according to a preset dividing mode; and calculating check codes corresponding to the file sets, determining positioning file data information in each file set, and storing the check codes and the positioning file data information into a block chain network. By the method for storing the evidence on the large file chain, all data corresponding to the target file is not required to be stored in the blockchain network, and the defect of data expansion is avoided. And introducing a check code and positioning file data information, and positioning tampered data in the target file when the stored target file is tampered.

The examples of the present specification also provide some specific embodiments of the method based on the method of fig. 2, which is described below.

Optionally, the method according to claim 1 may further comprise:

calculating the abstract value of the target file by adopting a hash algorithm;

the digest value is stored in the blockchain network.

It should be noted that, the blockchain network may also store a digest value corresponding to the target file, where the digest value is obtained by calculating the target file using a digest algorithm (also referred to as a hash algorithm or a hash algorithm). Digest algorithms are used to prevent tampering, for example: assume that the content in the target file is calculated by MD5, and the resulting inner digest value is A1. During verification, if the digest value corresponding to the acquired file is B, and is different from the digest of the original document, the target file can be determined to be tampered.

Since the digest function is a one-way function, a digest value of a fixed length is calculated for data of an arbitrary length through the digest function f (), but it is difficult to reversely extract the original data through the digest value. Slight changes to the original data will result in a completely different calculated summary. Thus, if the digest value is changed, it can be determined that the original data is tampered with.

In the method, the digest value corresponding to the target file is calculated and stored in the blockchain network, in the subsequent verification process, the digest value corresponding to the file to be verified can be calculated first, and compared with the digest value stored in the blockchain network, if the digest value is consistent with the digest value, the target file can be determined to be not tampered, and then the related step of subsequently locating tampered data in the file is not needed. If the digest values are inconsistent, the scheme in the embodiment of the present specification may be further adopted to locate tampered data in the target file.

Optionally, the storing the check code and the location file data information in the blockchain network may specifically include:

splicing the abstract value, the check code and the positioning file data information according to a preset splicing mode to obtain the evidence storage data corresponding to the target file;

The forensic data is stored in a blockchain network.

It should be noted that, when the target file is authenticated, the data stored in the blockchain network may be referred to as authentication data, where the authentication data may include a digest value, a check code, and information about the positioning file data. More specifically, the certification data may be obtained by splicing the digest value, the check code and the locating file data information. The splicing mode can be sequential splicing or splicing according to other preset modes.

In the method, the certification storage data corresponding to the target file is stored in the blockchain system, the abstract value in the certification storage data can preliminarily determine whether the target file is tampered, the file set obtained by dividing the target file when the target file is certificated can be determined by locating the file data information, and tampered data in the target file can be determined by the check code.

Optionally, the storing the certification data in the blockchain network may specifically include:

generating a certification certificate containing authentication information based on the certification data;

and sending the certification data containing the certification certificate to the blockchain network for storage.

It should be noted that, the certificate may correspond to a network address and/or a picture, so as to check the certificate corresponding to the certificate data; the certification certificate can be checked according to the web page or the picture corresponding to the network address, and the certification certificate is verified in the blockchain network so as to ensure the authenticity of the certification data.

Optionally, the dividing the plurality of file data into a plurality of file sets according to a preset dividing manner may specifically include:

dividing the plurality of file data into N file sets according to the preset number of files in the file sets; there is an order between the elements in each of the file sets.

After splitting the target file into a plurality of file data, the plurality of file data may be divided into a plurality of file sets, and when the splitting is performed, the plurality of file data may be divided into a plurality of file sets according to a preset number of files in each file set (for example, the number of files in each file set is 5).

The elements in each set may have a sequence, when splitting the target file, it may be understood that determining the data corresponding to each byte in the target file, where splitting does not affect the data of the original data in the target file, and the split data may not be stored, and the splitting step is only used for the step of dividing the original data into sets, so that multiple file data may be sequentially divided into multiple file sets, for example: the file data obtained after splitting the target file are A1, A2, A3, A4, A5, A6, A7, A8, A9, A10, A11, A12, A13 and A14, and when dividing, the number of elements in each file set is 5, and the set obtained after dividing according to the sequence is as follows: set 1= { A1, A2, A3, A4, A5}, set 2= { A6, A7, A8, A9, a10}, set 3= { a11, a12, a13, a14, \x 00}.

According to the method, the file data are divided into the file sets in sequence, so that the position of the tampered data can be positioned more quickly when the tampered condition of the target file is verified later.

Optionally, before calculating the check codes corresponding to the plurality of file sets, the method further includes:

arranging N file sets in a matrix form to obtain N rows and M columns of matrixes;

the calculating the check codes corresponding to the plurality of file sets may specifically include:

generating a corresponding check code for each row of the matrix corresponding to the plurality of file sets by adopting an erasure algorithm; and generating a corresponding check code for each column of file set of the matrix corresponding to the file sets.

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

This can be illustrated in connection with fig. 3:

fig. 3 is a schematic diagram of file set arrangement according to an embodiment of the present disclosure. As shown in fig. 3, a plurality of file sets may be numbered sequentially, for example: a is that ₁₁ 、A ₁₂ 、……、A _1n 、……、A ₂₁ 、A ₃₁ 、……、A _n1 Etc. and concatenating them into a matrix of N x N, the value of N being adjustable according to the particular situation. If there are remaining sets of files, the labels may be continued and spliced to the next N x N matrix. When the set of files is insufficient to fill the last N x N matrix, a set of fixed characters is used, such as: the file set composed of \x00 is filled, as in FIG. 3 Shown in the shaded portion of (a), a ₃₃ Partial character of (a) to A _nn Are filled with a set of documents consisting of fixed characters. Wherein, other fixed characters can be selected by the fixed character.

In performing the check code calculation, a check code may be selected to calculate the check code of each row and the check code of each column of the matrix in fig. 3, for example: the check code corresponding to the first row of the matrix in fig. 3 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 N line is RS _n The method comprises the steps of carrying out a first treatment on the surface of the The check code corresponding to the first column 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 N column is RS _n+n 。

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

When using the erasure correction algorithm, for example, using the RS algorithm, N (Data Shards) =50 and parity shards=2 are taken, then the original file (2/50) ×2=8% information is generated for erasure correction and verification; and can ensure that the original stored data (up to 2 file sets per row or column) can be recovered after any 4 file sets in the matrix are tampered.

By the method, when the file is stored, the file is subjected to block verification and storage, a verification code and a positioning code are introduced, and error correction is performed when the file is verified. Firstly, partitioning a file, and then sequentially arranging the partitions into a two-dimensional matrix of n x n; calculating check codes for each row and each column of the matrix respectively, and taking the first element of each matrix as a positioning code; the file summary check code and the positioning file data information are written in the blockchain to carry out verification, and the controllable storage cost is used for judging which file sets in the large file are modified and which are original contents, and still can provide untampered verification for correct or missing parts.

Example 2

Fig. 4 is a flow chart of a document authentication method according to an embodiment of the present disclosure.

The method can detect which fragments in the large file are modified in the verification stage, and can still provide unmodified evidence for unmodified fragments; further if the number of modified slices is small, it can be indicated in the verification phase how these slices are modified.

As shown in fig. 4, the process may include the steps of:

step 410: and acquiring positioning file data information and check codes corresponding to the file to be verified from the block chain network.

The check code can be obtained by calculating a plurality of file sets corresponding to the pre-stored target files; the plurality of file sets can be obtained by splitting the target file according to a preset splitting mode to obtain a plurality of file data and dividing the plurality of file data according to a preset dividing mode; the location file data information may include location information of location file data in the file set in the target file and content information of the location file data.

Specifically, the relevant content involved in this step can be referred to the explanation in embodiment 1, and will not be repeated here.

In the verification stage, according to the file identification of the file to be verified, the stored certification storage data corresponding to the file to be verified is obtained from the blockchain network. The verification data may include a digest value, a check code, and locating file data information of the file to be verified. The digest value may be calculated from a pre-stored object file.

Step 420: and determining a plurality of file sets corresponding to the files to be verified based on the positioning file data information.

In the verification stage, a plurality of file sets corresponding to the files to be verified can be determined according to a preset dividing mode used in the verification stage through the positioning file information stored in the blockchain network.

More specifically, the location information in the location file data information and the content information of the location file data may approximately locate the elements of the file set corresponding to the verification stage of the file to be verified, for example: determining the verification stage from the acquired positioning file data information, taking the first element in each file set as a positioning code, finding the first element in the file to be verified as the first element in the first set, and then according to the fixed element number in each set, for example: and 9, in the data corresponding to the file to be verified, sequentially searching for 9 elements from the first element, taking the 9 elements as a first file set, and analogically, and finding out a file set possibly corresponding to the file to be identified. And finally determining a plurality of file sets corresponding to the files to be verified.

Step 430: and calculating check codes corresponding to the plurality of file sets.

When the check codes corresponding to the file sets corresponding to the files to be verified are calculated, the file sets can be arranged in a matrix form, and the check codes corresponding to the file sets in each row in the matrix are calculated and the check codes corresponding to the file sets in each column are calculated.

Step 440: and comparing the calculated check codes corresponding to the plurality of file sets with the check codes obtained from the blockchain network to obtain a comparison result.

Step 450: and verifying the file to be verified based on the comparison result.

By comparing the check codes, the situation that the file set in a certain row and/or a certain column in the matrix is tampered can be determined. Therefore, the calculated check code can be compared with the check code obtained from the blockchain network, so that the tampered file set is positioned.

The method in fig. 4 includes acquiring positioning file data information and check codes corresponding to a file to be verified from a blockchain network; determining a plurality of file sets corresponding to the files to be verified based on the positioning file data information; calculating check codes corresponding to the plurality of file sets; comparing the calculated check codes corresponding to the plurality of file sets with the check codes obtained from the blockchain network to obtain a comparison result; and verifying the file to be verified based on the comparison result. The tampered data can be located by determining a specific tampered file set in the file to be verified from the certification data certificated in the blockchain network.

The present description example also provides some specific embodiments of the method based on the method of fig. 4, which is described below.

Optionally, the obtaining, from the blockchain network, the positioning file data information and the check code corresponding to the file to be verified may specifically include:

acquiring identification information corresponding to the file to be verified;

and acquiring positioning file data information and check codes corresponding to the file to be verified from the blockchain network based on the identification information.

It should be noted that, the identification information may represent information capable of uniquely identifying the document to be verified, based on the identification information, the certificate storage data corresponding to the document to be verified may be obtained from the blockchain network, further, in order to ensure the security of the certificate storage data, before the certificate storage data corresponding to the document to be verified is obtained based on the identification information, a requester requesting to obtain the certificate storage data corresponding to the document to be verified may be required to provide an authorization statement, where the authorization statement may be issued by a holder of the document to be verified, a specific address may be carried in the authorization statement, and when the certificate storage data obtaining request is received by the blockchain network, the authorization statement carried in the certificate storage data request may be audited, and after the audit is passed, the certificate storage data corresponding to the document to be verified may be provided to the requester based on the identification information in the request.

Optionally, before determining the plurality of file sets corresponding to the file to be verified based on the positioning file data information, the method further includes:

calculating the abstract value of the file to be verified by using a Hash algorithm used in the verification process;

comparing the calculated abstract value of the file to be verified with the abstract value in the evidence storage data;

when the calculated abstract value of the file to be verified is consistent with the abstract value in the evidence storage data, determining that the file to be verified is not tampered;

and when the calculated abstract value of the file to be verified is inconsistent with the abstract value in the evidence storage data, determining a plurality of file sets corresponding to the file to be verified based on the positioning file data information.

In practical application, when verifying whether a file is tampered and particularly tampered data, firstly judging whether the file is tampered, wherein the judging mode can be a mode of comparing the digest value, calculating the digest value of the file to be verified, comparing the digest value with the digest value of the target file acquired from the blockchain network, if the digest value is consistent, determining that the file to be verified is the corresponding target file in the process of storing the certificate, and if the file to be verified is not tampered, then no subsequent step of positioning tampered data is needed. In contrast, if the digest values are inconsistent, it can be determined that the file to be verified is a tampered file, and specific tampered data in the file to be verified can be further located.

Optionally, the determining, based on the positioning file data information, a plurality of file sets corresponding to the file to be verified may specifically include:

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

determining a second positioning file data set with coverage rate meeting preset conditions from the first positioning file set based on a dynamic programming algorithm;

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

determining a third positioning file data set according to the inconsistent positioning file data information so as to maximize the matching rate of the third positioning file data set and the pre-stored positioning file data;

and determining a plurality of file sets corresponding to the files to be verified based on the third positioning file data set.

It should be noted that, the first positioning file data set may represent all possible positioning code sets determined according to a fixed interval, and the second positioning file data set is a positioning code set based on a dynamic programming algorithm, where the determined matrix coverage rate meets a preset condition; the third positioning file data set is a final positioning code set obtained after the second positioning file data set is subjected to supplementary positioning.

In determining a plurality of file sets based on location file data information, the objective is to obtain location codes from the document data and to keep the matrix determined by the location codes in the authenticated file as consistent as possible with the matrix in the original file. The corresponding stages can be divided into preliminary positioning and supplementary positioning:

the preliminary positioning may be to find a matching sequence in the file according to a fixed interval between the file sets at the time of certification, so that the content covered by the matrix determined by the positioning code in the verified file is as much as possible. In practical application, when there are multiple arrangements so that coverage rates are the same, the overall matching rates of the matrices determined by the arrangements may be further compared, and a positioning code arrangement with the highest matching rate may 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); the description is given in connection with fig. 5:

fig. 5 is a schematic diagram of performing preliminary positioning based on positioning file data information according to an embodiment of the present disclosure.

As shown in fig. 5, in the authenticated file, the intervals between a11 and B11, between E11 and F11 and G11, and between H11 and I11 are all fixed intervals when the authentication is performed; there is an unassociated positioning code C11, D11 between B11 and E11 and there is data not covered by the matrix determined by the positioning code; while the positioning code H11 is located inside the matrix defined by the positioning code G11.

The supplementary positioning can be the supplement of the preliminary positioning, and when the positioning codes which are not determined in the positioning code sequence exist between two determined positioning codes in the verified file, the supplementary positioning is responsible for inserting the positioning codes between the two determined positioning codes of the verified file, so that the matching rate of each matrix is as high as possible. The description is given in connection with fig. 6:

fig. 6 is a schematic diagram of performing supplemental positioning based on positioning file data information according to an embodiment of the present disclosure.

As shown in fig. 6, a matrix defined by two positioning codes C11 and D11 is inserted between the positioning codes B11 and E11 by the supplementary positioning. For example: each positioning code is marked as a ₁ ,a ₂ ,…,a _n The matrix size determined by the positioning code in the verification process is L bytes, and the byte stream of the verified file is d1, d2, … and dm. Traversing the file byte by byte, if [ d ] is satisfied _i ,d _i+1 ,d _i+2 ,d _i+3 ]＝＝a _j (suppose a file is assembled of 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 The method comprises the steps of carrying out a first treatment on the surface of the Then a _j ,a _j+1 ,…,a _j+n-1 Is at [ d ] _i ,d _i+1 ,…,d _i+(n-1)*L+3 ]And an effective positioning interval. Recording all valid intervals on the authenticated file as per the byte stream location of the termination positioning code (d _i+(n-1)*L+3 ) Are arranged in ascending order as S ₁ ,S ₂ ,…,S _n Each interval has a length X ₁ ,X ₂ ,…,X _n . Length = number of positioning codes-1, start positioning code number a for each section ₁ ,a ₂ ,…,a _n And a termination location d in the authenticated document ₁ ,d ₂ ,…,d _n The method comprises the steps of carrying out a first treatment on the surface of the The question is converted into a sequence of intervals selected from S _R1 ,S _R2 ,…,S _Rm ]Satisfy a _i +X _i ≤a _i+1 And let X _R1 +X _R2 +…+X _Rm Maximum. This problem ignores a _i +X _i ≤a _i+1 When this is done, the following dynamic programming solution can be used.

Specifically, the case of data order adjustment in the authenticated file may be detected: record dp [ i ]]In order to be in the document to be authenticated,maximum cover length to ith byte, S _k For all the valid interval sets with i as the termination position, the state transition equation is: increase a _i +X _i ≤a _i+1 The conditions can be solved by the following two-dimensional dynamic programming.

And further can find a section sequence S in S _R1 ,S _R2 ,…,S _Rm ]Satisfy a _i +X _i ≤a _i+1 And let X _R1 +X _R2 +…+X _Rm Maximum; that is, according to the fixed interval of the positioning codes during the verification, the positioning codes are distributed in the original file, so that the content covered by the matrix determined by the positioning codes in the verified file can be as much as possible.

The undetermined positioning code in the recording interval is a ₁ ,a ₂ ,…,a _n The matrix size determined by the positioning code during verification is L bytes. The first step is to find the first positioning code a in the interval ₁ (find a if not found) ₂ Skip supplemental positioning when none is found); in the second step a ₁ Left and right finding a2 of +L (finding a3 if not found, left-most left to a1 position, right to end of interval); and step three, repeating the step two until the interval is finished or the next undetermined positioning code is not available. The positioning code position determined in the three steps is the positioning code which is determined in a complementary way.

Optionally, the calculating the check codes corresponding to the plurality of file sets may specifically include:

generating corresponding row check codes for a plurality of file sets corresponding to each row of the matrix by adopting an erasure algorithm; and generating corresponding column check codes for a plurality of file sets corresponding to each column of the matrix.

When the check codes corresponding to the plurality of file sets are calculated, the matrix corresponding to the plurality of file sets can be determined first, and then the check codes corresponding to each row and each column in the matrix are calculated for the matrix:

specifically, starting from each positioning code (such as a11, B11, C11), the data following the positioning code is divided according to the file data division mode (for example, 4 bytes) of each set when the storage is verified until the next positioning code. If the data cannot fill one set of files until the next location code, the remaining portion of the last set of files is filled with fixed bytes at the time of certification, such as \x00.

And restoring the N matrix used for the certificate through each positioning code and the corresponding file set thereof. If the number of the data file sets exceeds the number of the file sets of the certification matrix N by the next positioning code, the multiple file sets are used as the inserted data marks; if the number of file sets is insufficient, filling the subsequent file sets with fixed bytes, e.g., \x00, determined at the time of the certification, and rounding up the N x N matrix, and treating the missing file sets as missing data markers.

And then when the check codes of a plurality of file sets corresponding to the files to be verified are calculated, the check codes of each row and each column of each matrix are calculated respectively by using the check codes or the Hash function in the process of storing the certificates, and the check codes are compared with the check codes stored in the process of storing the certificates, so that the modified file set is positioned. This can be explained in connection with fig. 6:

fig. 7 is a schematic diagram of verification based on a check code according to an embodiment of the present disclosure.

As shown in fig. 7, for example: when the check code of the matrix is calculated and compared with the check code obtained in the block chain network, RS is found ₁ 、RS ₃ 、RS _n+1 、RS _n+n If the value of the check code is inconsistent with that of the check code in the verification, the check code can represent a file set A in a matrix ₁₁ 、A _1n 、A ₃₁ 、A _3n Is inconsistent with the content of the certificate in the time of the certificate.

Further, comparing the calculated check codes corresponding to the plurality of file sets with the check codes obtained from the blockchain network to obtain a comparison result, which specifically may include:

for a plurality of file sets of an ith row in the matrix, acquiring row check codes corresponding to the file sets of the ith row from the blockchain network;

comparing the calculated row check codes corresponding to the file sets of the ith row with row check codes corresponding to the file sets of the ith row acquired from the blockchain to obtain row check code comparison results;

For a plurality of file sets of a j-th column in the matrix, acquiring column check codes corresponding to the file sets of the j-th column from the blockchain network;

and comparing the calculated column check codes corresponding to the plurality of the file sets in the j-th column with the column check codes corresponding to the plurality of the file sets in the j-th column acquired from the blockchain to obtain a column check code comparison result.

It should be noted that, after comparing the check codes of each row of the matrix and comparing the check codes of each column of the matrix, specific tampered data may be determined, for example: by comparing the row check codes, the inconsistent check codes of the 3 rd row in the matrix are determined, and by comparing the column check codes, the inconsistent check codes of the 2 nd column are determined, so that the data at the 2 nd column of the 3 rd row in the matrix can be determined to be tampered.

Alternatively, if the algorithm used in calculating the check code is an erasure algorithm, part of the modified data may be recovered by the check code. For example, when using the RS algorithm, N (Data Shards) =50 and parity boards=2, then when the number of modified file sets in a certain row or a certain column is 2 or less; the modified file set in the row or column can be restored by the RS algorithm based on the other values and check codes of the row or column.

The technical effects that can be achieved in the above two embodiments are as follows:

1) In the scheme of large file Hash uplink certification, a verifier cannot know which part of the file is tampered, and only can obtain the final result whether the whole file is consistent with the original result. According to the technical scheme, independent verification can be carried out on each file set of a single large file, and controllable storage cost is used for judging which file sets in the large file are modified and which are original contents. In this way, the modified file set content can be directly found during verification, and other contents can still prove that the modified file set content is not tampered.

2) Since Hash up-link certificates do not store the original file, the source file is hosted in an external system. The external system has a very small probability of possibly causing the damage of the file part, for example, when using a magnetic disk for storage, data errors are caused after the magnetic poles are reversed, or data loss is caused after a bad track is formed, etc. The solution in the embodiments of the present description still provides tamper-proof for correct or non-missing parts; further, when tampered data or lost data occupies a small part of the sorted data, the lost or tampered data can be restored by storing the certification information.

Based on the same thought, the embodiment of the specification also provides a device corresponding to the method. Fig. 8 is a schematic structural diagram of a document storage device according to an embodiment of the present disclosure. As shown in fig. 8, the apparatus may include:

the target file obtaining module 810 is configured to obtain a target file to be authenticated;

a file data determining module 820, configured to split the target file according to a preset splitting manner, so as to obtain a plurality of split file data;

a file set dividing module 830, configured to divide the plurality of file data into a plurality of file sets according to a preset division manner; each file set comprises m elements;

a check code calculation module 840, configured to calculate check codes corresponding to the plurality of file sets;

a locating file data information determining module 850 for determining locating file data information in each of the file sets; the positioning file data information comprises the position information of positioning file data in the file set in the target file and the content information of the positioning file data;

the data storage module 860 is configured to store the check code and the location file data information in a blockchain network.

The present examples also provide some embodiments of the method based on the apparatus of fig. 8, as described below.

Optionally, the apparatus may further include:

the digest value calculation module is used for calculating the digest value of the target file by adopting a hash algorithm;

and the digest value storage module is used for storing the digest value in the blockchain network.

Optionally, the data storage module 860 may specifically include:

the verification data determining unit is used for splicing the abstract value, the check code and the positioning file data information according to a preset splicing mode to obtain the verification data corresponding to the target file;

and the certification data storage unit is used for storing the certification data in the blockchain network.

Optionally, the certification data storage unit may be specifically configured to:

Optionally, the file set partitioning module 830 may specifically include:

the dividing unit is used for dividing the plurality of file data into N file sets according to the preset number of the file sets; there is an order between the elements in each of the file sets.

Optionally, the apparatus may further include:

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

the check code calculation module specifically comprises:

the check code calculation unit is used for generating corresponding check codes for each row of the matrixes corresponding to the plurality of file sets by adopting an erasure correction algorithm; and generating a corresponding check code for each column of file set of the matrix corresponding to the file sets.

Optionally, the locating file data information determining module 850 may specifically include:

and the locating file data information determining unit is used for determining elements at specific positions in each group of file sets as locating file data to obtain a locating file data set.

Based on the same thought, the embodiment of the specification also provides a device corresponding to the method. Fig. 9 is a schematic structural diagram of a document verification device according to an embodiment of the present disclosure. As shown in fig. 9, the apparatus may include:

the data acquisition module 910 is configured to acquire positioning file data information and a check code corresponding to a file to be verified from the blockchain network; the check code is obtained by calculating a plurality of file sets corresponding to the pre-stored target files; the plurality of file sets are obtained by splitting the target file according to a preset splitting mode to obtain a plurality of file data and dividing the plurality of file data according to a preset dividing mode; the positioning file data information comprises the position information of positioning file data in the file set in the target file and the content information of the positioning file data;

A file set determining module 920, configured to determine a plurality of file sets corresponding to the file to be verified based on the positioning file data information;

a check code calculation module 930, configured to calculate check codes corresponding to the plurality of file sets;

a comparison module 940, configured to compare the check codes corresponding to the plurality of file sets obtained by calculation with the check codes obtained from the blockchain network to obtain a comparison result;

and the verification module 950 is configured to verify the file to be verified based on the comparison result.

The present description example also provides some embodiments of the method based on the apparatus of fig. 9, as described below.

Optionally, the data acquisition module 910 may specifically include:

the identification information acquisition unit is used for acquiring identification information corresponding to the file to be verified;

and the data acquisition unit is used for acquiring the positioning file data information and the check code corresponding to the file to be verified from the blockchain network based on the identification information.

Optionally, the apparatus may further include:

the digest value calculation module is used for calculating the digest value of the file to be verified by using a Hash algorithm used in the process of storing the certificate;

The digest value comparison module is used for comparing the digest value of the file to be verified obtained through calculation with the digest value in the certificate storage data;

a tamper condition determining unit, configured to determine that the file to be verified is not tampered when the calculated digest value of the file to be verified is consistent with the digest value in the certificate storing data; and when the calculated abstract value of the file to be verified is inconsistent with the abstract value in the evidence storage data, determining a plurality of file sets corresponding to the file to be verified based on the positioning file data information.

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 position information;

the second positioning file data set determining unit is used for determining a second positioning file data set with coverage rate meeting preset conditions from the first positioning file set based on a dynamic programming algorithm;

the positioning file data information comparison unit is used for comparing the second positioning file data set with the pre-stored positioning file data information and determining inconsistent positioning file data information;

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

and the file set determining unit is used for determining a plurality of file sets corresponding to the files to be verified based on the third positioning file data set.

Optionally, the check code calculation module 930 may specifically include:

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

the verification code generation unit is used for generating corresponding row verification codes for the plurality of file sets corresponding to each row of the matrix by adopting an erasure algorithm; and generating corresponding column check codes for a plurality of file sets corresponding to each column of the matrix.

Optionally, the comparison module 940 may be specifically configured to:

Based on the same thought, the embodiment of the specification also provides equipment corresponding to the method.

Fig. 10 is a schematic diagram of a document authentication and verification device according to an embodiment of the present disclosure. As shown in fig. 10, the apparatus 1000 may include:

at least one processor 1010; the method comprises the steps of,

a memory 1030 communicatively coupled to the at least one processor; wherein,,

the memory 1030 stores instructions 1020 executable by the at least one processor 1010

Corresponding to embodiment 1, the instructions 1020 are executable by the at least one processor 1010 to enable the at least one processor 1010 to:

calculating check codes corresponding to the plurality of file sets;

Corresponding to embodiment 2, the instructions 1020 are executable by the at least one processor 1010 to enable the at least one processor 1010 to:

calculating check codes corresponding to the plurality of file sets;

and verifying the file to be verified based on the comparison result.

Based on the same thought, the embodiment of the specification also provides a computer readable medium corresponding to the method. A computer readable medium has stored thereon computer readable instructions executable by a processor to implement the following method, corresponding to embodiment 1:

calculating check codes corresponding to the plurality of file sets;

Corresponding to embodiment 2, the computer readable instructions are executable by a processor to implement the method of:

calculating check codes corresponding to the plurality of file sets;

And verifying the file to be verified based on the comparison result.

In this specification, each embodiment is described in a progressive manner, and identical and similar parts of each embodiment are all referred to each other, and each embodiment mainly describes differences from other embodiments. In particular, for the apparatus embodiments, since they are substantially similar to the method embodiments, the description is relatively simple, and reference is made to the description of the method embodiments in part.

In the 90 s of the 20 th century, improvements to one technology could clearly be distinguished as improvements in hardware (e.g., improvements to circuit structures such as diodes, transistors, switches, etc.) or software (improvements to the process flow). However, with the development of technology, many improvements of the current method flows can be regarded as direct improvements of hardware circuit structures. Designers almost always obtain corresponding hardware circuit structures by programming improved method flows into hardware circuits. Therefore, an improvement of a method flow cannot be said to be realized by a hardware entity module. For example, a programmable logic device (Programmable Logic Device, PLD) (e.g., field programmable gate array (Field Programmable Gate Array, FPGA)) is an integrated circuit whose logic function is determined by the programming of the device by a user. The designer programs itself to "integrate" a digital system onto a single PLD without requiring the chip manufacturer to design and fabricate application specific integrated circuit chips. Moreover, nowadays, instead of manually manufacturing integrated circuit chips, such programming is mostly implemented by using "logic compiler" software, which is similar to the software compiler used in program development and writing, and the original code before the compiling is also written in a specific programming language, which is called hardware description language (Hardware Description Language, HDL), but not just one of the hdds, but a plurality of 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., VHDL (Very-High-Speed Integrated Circuit Hardware Description Language) and Verilog are currently most commonly used. It will also be apparent to those skilled in the art that a hardware circuit implementing the logic method flow can be readily obtained by merely slightly programming the method flow into an integrated circuit using several of the hardware description languages described above.

The controller may be implemented in any suitable manner, for example, the controller may take the form of, for example, a microprocessor or processor and a computer readable medium storing computer readable program code (e.g., software or firmware) executable by the (micro) processor, logic gates, switches, application specific integrated circuits (Application Specific Integrated Circuit, ASIC), programmable logic controllers, and embedded microcontrollers, examples of which include, but are not limited to, the following microcontrollers: ARC 625D, atmelAT91SAM, microchip PIC18F26K20, and Silicone Labs C8051F320, the memory controller may also be implemented as part of the control logic of the memory. Those skilled in the art will also appreciate that, in addition to implementing the controller in a pure computer readable program code, it is well possible to implement the same functionality by logically programming the method steps such that the controller is in the form of logic gates, switches, application specific integrated circuits, programmable logic controllers, embedded microcontrollers, etc. Such a controller may thus be regarded as a kind of hardware component, and means for performing various functions included therein may also be regarded as structures within the hardware component. Or even means for achieving the various functions may be regarded as either software modules implementing the methods or structures within hardware components.

The system, apparatus, module or unit set forth in the above embodiments may be implemented in particular by a computer chip or entity, or by a product having a certain function. One typical implementation is a computer. In particular, the computer may be, for example, a personal computer, a laptop computer, a cellular telephone, 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 convenience of description, the above devices are described as being functionally divided into various units, respectively. Of course, the functions of each element may be implemented in the same piece or pieces of software and/or hardware when implementing the present application.

It will be appreciated by those skilled in the art that embodiments of the present application may be provided as a method, system, or 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, and the like) 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 flow and/or block of the flowchart illustrations and/or block diagrams, and combinations of flows 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 a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

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

The memory may include volatile memory in a computer-readable medium, random Access Memory (RAM) and/or nonvolatile memory, such as Read Only Memory (ROM) or flash memory (flash RAM). Memory is an example of computer-readable media.

Computer readable media, including both non-transitory and non-transitory, removable and non-removable media, may implement information storage by any method or technology. The information may be computer readable instructions, data structures, modules of a program, or other data. Examples of storage media for a computer 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 Discs (DVD) or other optical storage, magnetic cassettes, magnetic tape disk storage or other magnetic storage devices, or any other non-transmission medium, which can be used to store information that can be accessed by a computing device. Computer-readable media, as defined herein, does not include transitory computer-readable media (transmission media), such as modulated data signals and carrier waves.

It should also be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article or apparatus that comprises the element.

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 memory storage devices.

The foregoing is merely exemplary of the present application and is not intended to limit the present application. Various modifications and variations of the present application will be apparent to those skilled in the art. Any modification, equivalent replacement, improvement, etc. which come within the spirit and principles of the application are to be included in the scope of the claims of the present application.

Claims

1. A document forensic method comprising:

obtaining a target file to be stored;

dividing the plurality of file data into a plurality of file sets according to a preset dividing mode;

calculating check codes corresponding to the plurality of file sets;

2. The method of claim 1, further comprising, prior to calculating the check codes corresponding to the plurality of file sets:

Arranging the plurality of file sets in a matrix form to obtain a matrix of N rows and M columns;

the calculating the check codes corresponding to the plurality of file sets specifically includes:

generating a corresponding check code for each row of a matrix corresponding to the plurality of file sets; and generating a corresponding check code for each column of file set of the matrix corresponding to the file sets.

3. The method of claim 1, further comprising:

calculating the abstract value of the target file by adopting a hash algorithm;

the digest value is stored in the blockchain network.

4. A method according to claim 3, wherein said storing said check code and said location file data information in a blockchain network, in particular comprises:

the forensic data is stored in a blockchain network.

5. The method according to claim 4, wherein the storing the certification data in the blockchain network specifically comprises:

6. 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:

7. The method of claim 2, wherein the calculating check codes corresponding to the plurality of file sets specifically includes:

8. The method according to claim 1, wherein said determining locating file data information in each of said file sets comprises:

9. A document authentication method comprising:

calculating check codes corresponding to the plurality of file sets;

and verifying the file to be verified based on the comparison result.

10. The method of claim 9, the check code is a corresponding check code generated for each row of a matrix corresponding to the plurality of sets of files and a corresponding check code generated for each column of a set of files of the matrix corresponding to the plurality of sets of files; the matrix is formed by arranging the plurality of file sets in a matrix form to obtain a matrix of N rows and M columns.

11. The method of claim 9, wherein the obtaining, from the blockchain network, the locating file data information and the check code corresponding to the file to be verified, specifically includes:

acquiring identification information corresponding to the file to be verified;

12. The method of claim 9, further comprising, before determining the plurality of file sets corresponding to the file to be verified based on the positioning file data information:

13. The method according to claim 9, wherein the determining, based on the locating file data information, a plurality of file sets corresponding to the file to be verified specifically includes:

14. The method of claim 10, wherein the calculating check codes corresponding to the plurality of file sets specifically includes:

arranging the file sets in a matrix form to obtain a matrix of N rows and M columns;

15. The method of claim 14, wherein comparing the calculated check codes corresponding to the plurality of file sets with the check codes obtained from the blockchain network to obtain a comparison result, specifically includes:

16. A document forensic device comprising:

the file set dividing module is used for dividing the plurality of file data into a plurality of file sets according to a preset dividing mode;

17. A document authentication apparatus comprising:

18. A document forensic device comprising:

at least one processor; the method comprises the steps of,

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

calculating check codes corresponding to the plurality of file sets;

19. A document authentication apparatus comprising:

at least one processor; the method comprises the steps of,

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

calculating check codes corresponding to the plurality of file sets;

and verifying the file to be verified based on the comparison result.

20. 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 15.