RU2792258C1 - Method for protecting electronic documents in text format presented on solid storage carriers - Google Patents

Abstract

FIELD: information security.

SUBSTANCE: invention relates to the field of information security using cryptographic tools. The effect is achieved due to the fact that an electronic signature and a block of redundant information are formed from an electronic document file of the original format, then the set of a block of redundant information, an electronic signature is defined as an improved electronic signature. The digitally generated advanced electronic signature block and the verification key are defined as arbitrary symbols of the modular code, an encoding operation is performed, the result of which is to obtain a redundant symbol of the modular code. Next, the stage of error-correcting coding of the received symbols of the modular code is performed. The improved electronic signature, the verification key and the generated redundant symbol of the modular code are converted from digital form into a group of three bar codes, which, together with the content of the source text, are applied to paper.

EFFECT: ensuring the possibility of verifying the authenticity and integrity of electronic documents in text format, presented on solid media in case of damage and (or) exclusion of one of the bar codes from the electronic document.

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Description

The field of technology.

The invention relates to the field of information security using cryptographic means, in particular to a legally significant workflow.

The level of technology.

a) description of analogues

There is a known method for verifying the authenticity of information "Method for controlling the integrity and authenticity of electronic documents in text format presented on solid media" (RF patent No. 2591655, class G06F 21/64, H04L 9/32, G06K 9/00, publ. 2016). In a known method, control information is generated in digital form. Sign her EP. The received information is converted from a digital form into a bar code. It is applied to the object, and when read, the barcode is converted into digital form. Allocate from it ES and control information. Check the authenticity of the electronic signature and information at the facility. A paper carrier with text information printed on it is used as an object, and all text information or a part of text information is used as control information (CI). In addition, the public key for verifying the ES is additionally converted into a barcode, which is also applied to paper and used to authenticate the ES. At the same time, if the ES is genuine, then the CI extracted from the bar code is visually compared with the text information printed on paper, and based on the results of the comparison, a conclusion is made about the authenticity of the text information printed on paper.

The disadvantage of this method is the need for human participation directly in the process of verifying the authenticity of information presented on a hard drive, which reduces the efficiency and reliability of the verification result.

b) description of the closest analogue (prototype).

The closest in technical essence to the claimed invention and taken as a prototype is a method for monitoring the integrity and authenticity of electronic documents in a text format presented on solid media (See Pat. RF No. 2591655, class G06F 21/64, H04L 9/32, G06K 9/00, published 2016). In the known method, the source file of the text format ED is formed in the format of the markup language, and it is defined as the ED of the original format. From the received ED file of the original format, an ES is formed. Next, redundant error-correcting coding algorithms are applied to the ED file of the original format. The result of error-correcting coding is defined as a block of redundant information (RI). The resulting ES value, the ES verification key value, and the AI block are defined as an advanced ES (EC). Next, the UEP is converted from a digital (electronic) form into a bar code, the bar code and the content of the text document of the original format are applied in a form accessible to human perception on a solid (for example, paper) information carrier. When checking the integrity and authenticity of an ED in a text format presented on a solid medium, the barcode containing the UES and the text of the document are converted into digital (electronic) form, the value of the ES, the ES verification key and the AI block are extracted from the digital form of the UES, the procedure for recognizing the digital graphic image of the text of the document. The ED file of an arbitrary text format obtained after the recognition procedure is converted into an ED file of the original format. Further, using the AI block, the integrity of the ED file of the original format is restored and the integrity and authenticity of the text document are checked using standard software tools. In the case of a positive result of the ES check, the ED file of the original format obtained after the conversion is recognized as complete and authentic. After that, the content (text) of the verified ED and the value of the SEC, presented in the form of a bar code, are again applied to a solid carrier, and it is this set that is recognized as a genuine and complete ED presented on a solid carrier. At the same time, the original ED presented on a hard carrier, on the basis of which the ED file of the original format is obtained, is considered as an auxiliary element and is not an object of integrity and authenticity verification.

The disadvantage of the prototype is the impossibility of implementing the method described in it in case of damage to any of the bar codes.

Disclosure of the essence of the invention

a) the technical result to which the invention is directed.

The technical result of the claimed invention is to provide the possibility of verifying the authenticity and integrity of electronic documents in text format, presented on solid media in the event of damage and (or) exclusion of one of the bar codes from the electronic document.

b) a set of essential features

The formulated technical result is achieved by the fact that in the known method, the source file of the text format ED is formed in the format of the markup language, and it is defined as the ED of the original format. From the received ED file of the original format, an ES is formed. Next, noise-correcting coding algorithms are applied to the ED file of the original format. The result of error-correcting coding is defined as a block of redundant information (RI). The obtained value of the EP, the AI block is defined as an improved EP (C _uep ). Next C _wep and key verification K _prov . converted from digital form into separate barcodes (Fig. 1).

When reading, the procedure for recognizing bar codes With _uep and the verification key K _prov. , convert the barcode C _UEp and K _prov. into digital form, the value of EP is extracted from C _uep . Next, the ED is converted to the original format with the restoration of integrity due to the AI block from the C _ep. and check the integrity and authenticity of the document using standard software tools (Fig. 2).

A comparative analysis of the claimed solution with the prototype shows that the proposed method differs from the known one in that the digitally generated block C _uep and the verification key K _prov. , are defined as arbitrary symbols of the modular code (MC) and _i ,

where index i is the number of the corresponding block of data enclosed in one bar code. The set of block C _uep and verification key K _prov. , we will represent it as a sequence of the smallest non-negative symbols of MK, under the condition α ₁ <m ₁ , α ₂ <m ₂ , and GCD (m ₁ ,m ₂ )=1 and m ₁ <m ₂ . Then we have a system of comparisons:

where X has a unique solution:

(CRT is the operator of the solution of the system of comparisons in accordance with the Chinese remainder theorem).

Next, the encoding operation (CD-1) is performed by introducing an additional module m ₃ :

The result of encoding is to obtain a redundant symbol MK m ₃ .

по известным алгоритмам предусмотренных стандартами штрихового кодирования (код Рида-Соломона, БЧХ код и т.п.). Результатом кодирования является получение кодовых слов данных и кодовых слов обнаружения ошибок в отдельно взятом символе МК.Next, the stage of error-correcting coding (KD-2.1, KD-2.2, KD-2.3) of the received MC symbols is performed.

according to known algorithms provided by bar coding standards (Reed-Solomon code, BCH code, etc.). The result of encoding is to obtain data code words and error detection code words in a single MC symbol.

Advanced electronic signature C _wep , verification key K _prov. and the generated redundant symbol MK a ₃ is converted from digital

forms into a group of three barcodes C _wep , K _prov. , I _excess. , by graphical transformation (KD-3.1, KD-3.2, KD-3.3) (Fig. 3).

The extension operation endows the method with the properties of guaranteed error correction within a single bar code, provided that the multiplicity of corrected errors exceeds the corrective capabilities of existing error-correcting coding methods used in bar coding standards.

, где символ * - указывает на возможные ошибки.When reading bar codes, optical recognition is performed (DK-3.1, DK-3.2, DK-3.3) and the restoration of data code words and error detection. Next, the data is decoded (DK-2.1, DK-2.2, DK-2.3), known algorithms provided by the bar coding standards. The result of decoding is the receipt of the MK symbol system:

, where the symbol * - indicates possible errors.

из системы символов МК в котором имеется ошибка (ошибки):If an error is fixed as a result of decoding or the barcode is not decoded, then in accordance with the Chinese Remainder Theorem, the distorted MK symbol (barcode) is restored by eliminating the module

from the MK symbol system in which there is an error (errors):

The result of this step will be an array of possibly corrected MK symbols. The received content C _wep , K _prov. they convert it into digital form, extract an electronic signature from the _SUEP and verify the authenticity of the ES and ED of the original format (Fig. 4).

c) a causal relationship between the features and the technical result.

Thanks to a new set of essential features, the method implements the possibility of increasing the efficiency and ensuring the reliability of verifying the authenticity of information on paper in the event of a complete or partial violation of the barcode image.

Evidence of compliance of the claimed invention with the conditions of patentability "novelty" and "inventive step".

The analysis of the prior art made it possible to establish that there are no analogues characterized by a set of features identical to all the features of the claimed technical solution, which indicates that the claimed device complies with the patentability condition "novelty".

The results of the search for known solutions in this and related fields of technology in order to identify features that match the distinguishing features of the prototype of the claimed object showed that they do not follow explicitly from the prior art. From the prior art also not revealed the fame of the distinctive essential features that cause the same technical result, which is achieved in the claimed method. Therefore, the claimed invention meets the condition of patentability "inventive step".

Brief description of the drawings

The claimed method is illustrated by drawings:

fig. 1 - the procedure for generating bar codes of an improved electronic signature and a verification key in accordance with the prototype;

fig. 2 - the order of reading the barcodes of the improved electronic signature and verification key in accordance with the prototype;

fig. 3-procedure for generating bar codes of an improved electronic signature, a verification key and a redundant bar code in accordance with the claimed method;

fig. 4 - the procedure for reading the bar codes of the improved electronic signature, the verification key and the redundant bar code in accordance with the claimed method.

Implementation of the invention.

The claimed method is carried out as follows.

From the ED file of the original format, an ES is formed. Next, redundant error-correcting coding algorithms are applied to the ED file of the original format (for example, the use of BCH codes or other known correction codes). The result of error-correcting coding is defined as a block of redundant information (RI). The obtained value of the EP, the AI block is defined as an improved EP (C _uep ). Next C _wep and check key K _prov. are defined as arbitrary symbols of the MC of the modular code (MC). The coding procedure (CD-1) is performed using the redundant MC. The result of encoding is to obtain a redundant MC symbol. For each MK symbol, an error-correcting coding algorithm provided by the bar coding standard is applied (for example, the use of Reed-Solomon codes, BCH codes, etc.). Next, the obtained blocks are converted into a two-dimensional bar code (for example, a two-dimensional QR code), which is printed on the document.

All operations for the formation of a two-dimensional bar code symbol, its recognition, scanning are performed automatically using existing software and hardware.

The ES is formed from the original ED file according to the standard cryptographic algorithm (GOST R 34.10-2012).

When reading two-dimensional bar codes, the procedure for recognizing a graphic image of digital forms containing UEP and a verification key is performed. Further, using the noise-correcting coding algorithm provided by the bar coding standard, the decoding procedure is performed. In the case of a positive result, the content With _uep , K _prov . convert it into digital form, extract an electronic signature from the _SUEP and verify the authenticity of the ES and ED of the original format

If the multiplicity of the error of one block (MK symbol) exceeds the multiplicity of the corrected error of the error-correcting code (Reed-Solomon, BCH code, etc.), then the procedure for recognizing the graphic image of the redundant block (MK symbol) is performed, the redundant digital form is isolated with further error correction (Fig. 4).

The positive effect of the method claimed as an invention is provided by the use of additional redundant coding while ensuring the reliability and efficiency of the authentication result at the level provided by digital means of information processing, which was previously not available to users of information systems processing documents on hard media.

Claims (1)

A method for protecting electronic documents in a text format presented on solid information carriers, which consists in the fact that the control information in digital form is formed in the format of a markup language and this set is defined as an electronic document file of the original format, then an electronic signature is formed from the file of the electronic document of the original format, additionally, using error-correcting coding methods, a block of redundant information is formed from the file of an electronic document of the original format, then the set of block of redundant information, the electronic signature is defined as an improved electronic signature, which is converted from digital form into a bar code, the resulting bar code and the content of the electronic document presented in in a human-readable form is fixed on a hard carrier, when checking a document presented on a hard carrier, a bar code containing an improved electronic signature is converted , and the text of the document into digital form, extract the value of the electronic signature, the electronic signature verification key and the block of redundant information from the digital form of the improved electronic signature, perform the procedure for recognizing the digital graphic image of the document text, apply the procedure to the file of the electronic document of an arbitrary text format obtained after the recognition procedure restoring the original format of an electronic document file, while using a block of redundant information, then performing a standard procedure for verifying the authenticity and integrity of the received file of an electronic document of the original format using an electronic signature in automatic mode, characterized in that the digitally generated block of an improved electronic signature and a key checks are presented as symbols of a modular code, taken according to a system of pairwise simple modules, the encoding procedure is carried out by introducing an additional module and obtaining of the redundant symbol of the modular code, the set of received symbols is defined as a modular code, then the symbols of the modular code are encoded in accordance with the known error-correcting coding algorithms defined by the standard for the selected symbolism of the bar code, at the next step, the improved electronic signature, the verification key and the redundant symbol of the modular code are converted from a digital form into a group of three bar codes, put them on paper, and when reading each bar code is converted into a digital form, a procedure for checking the correctness of reading is performed, while the well-known noise-immune coding algorithms provided for by the bar code standard are used as error detection in a single barcode, then, if an error is present, the error is corrected using a modular code, after which an improved electronic signature and a verification key are isolated, while further verification is performed the integrity and authenticity of the electronic signature and the electronic document of the original format in automatic mode, in case of a positive result of the verification of the electronic signature, the electronic document of the original format is recognized as authentic.

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