RU2656734C2 - Method of digital information in the form of ultra-compressed nano bar code encoding and decoding (options) - Google Patents

Abstract

FIELD: general-purpose electronic circuits.

SUBSTANCE: invention relates to the digital information conversion (encoding), decoding and recording method to form the matrix ultra-compressed two-dimensional code (nano bar code), as well as to optically readable two-dimensional codes representing binary coded data placed on the two-dimensional matrix and thus forming the information placement template. Disclosed is the digital information encoding method in form of the ultra-compressed code, nano bar code, comprising reception of information to be encoded, encoding information using the code conversion table, and obtaining code message on the information storage medium in the form of physical or electronic code, at that, after the information encoding, performing its encryption, compression, and redundant information addition for recovery in the event of its loss, information encryption is performed using cryptographic algorithms in two stages, at the first stage, encryption is performed at the bytes level using the poly-alphabetic byte cipher with the different offset value for each byte of information, at the second stage, the encryption is performed at the bits level based on the symmetric bit encryption algorithm AES, information compression is performed based on the optimal codes methods, wherein the probabilities of the code words occurrence for each block of encoded information are calculated only for this block and are recalculated for each block, to obtain the code message, performing the encoded data structure formation in the form of the ultra-compressed nano bar code.

EFFECT: technical result is increase in the reliability of information encoding in the form of the ultra-compressed nano bar code with ability of the information encryption.

20 cl, 25 dwg, 7 tbl

Description

The present invention relates to a method for converting (encoding), decoding, and recording digital information to generate a matrix ultra-compressed two-dimensional code (nanobar code), as well as optically readable two-dimensional codes representing binary-coded data placed on a two-dimensional matrix and forming, thus , template for posting information. In this case, the binary-coded data is divided into binary blocks with a cryptographically converted, packed with compression algorithms and supplemented with information recovery algorithms for lost data. Also, the present invention will find application in the field of protection against counterfeiting of mass-produced products, and, in particular, in the field of identification of the authenticity of goods in the system of protection against counterfeiting.

There are various technical solutions in this area.

So, for example, in patent RU No. 2321890 (IPC G06Q 30/00, published on April 10, 2008), an open N-digit number is used, which makes it easy to copy, and in addition to product information, an open N-digit number carries additional codes of information (for example, advertising), which during authentication will lead to the verification of extra information, and storing additional information in the database will require additional hardware.

RU patent No. 2323474 (IPC G06K 1/00, G09F 3/00, published. 04/27/2008) uses multiple hidden application of unique numbers under erasable opaque layers, however, when checking, in addition to the unique number, you must enter the serial number of the strip on which the mentioned number is applied. The introduction of a large number of numbers can be difficult for the user to verify the authenticity of the goods.

Patent RU No. 2183349 (IPC G06K 1/12, G06K 9/00, published. 06/10/2002) uses a large amount of information encrypted in various ways on the sticker. When checking, special equipment is required, which makes it difficult for end users to use this system.

Thus, the most functional is the use of barcodes that perform protective and identifying functions.

In RU patent No. 2349957 “Mixed code, and a method and device for generating it, and a method and device for decoding it” (IPC G06K 19/06, G09F 3/02, published. 03.20.2009), the code is represented by a physical or electronic image. The location of the information blocks in the known mixed code is not rational from the point of view of information recovery or image capture code. If these areas are damaged, it is impossible to scan or decode the code.

Another type of machine-readable code that meets the level of modern requirements is described in GB patent No. 2383878 (IPC: B41F 9/00; B41M 1/10; B41M 3/14; B42D 15/00; B42D 15/10; B65B 61/28; G07D 7/12; G09F 3/00; G09F 3/03, published 09.07.2003). The advantages of this type of code among other trading machine-readable codes lie in a very high degree of filling with all kinds of separate codes, as well as in the ability to create individual codes. The disadvantage of this patent is the lack of a unique design of the matrix code (known symbols are used), as well as the lack of protective algorithms to prevent unauthorized decoding of information placed in this machine-readable code.

Known patents US No. 6279830 (IPC: G06K 17/00; G06K 19/00; G06K 19/06; G06K 7/00; G06K 7/10, published. 08/28/2001) and US No. 5591956 (IPC: G06K 17/00 ; G06K 19/06; G06K 7/10; G06K 7/14, published. 01/07/1997) on various two-dimensional symbols. The main features of these matrix codes are: a fairly high density of information, the ability to encode text, byte and digital information. Such codes contain data blocks in the form of a matrix of alternating black and white squares, an information recovery unit, a text, byte, and digital information compression unit. A disadvantage of the known patents is also the lack of security algorithms to prevent unauthorized decoding of the information contained in this machine-readable code. In addition, well-known algorithms are used to form information recovery blocks.

A well-known method for reading a two-dimensional code includes the steps of taking an image of a two-dimensional code using an image input device, such as a photo and television camera, and then determining the position of the corresponding two-dimensional code for reading the contents of the code. To capture the image area of a two-dimensional code, areas of sharp brightness change are used - the finding of such areas can be organized based on the analysis of the first and second derived images. Further, the image is fragmented and individual cells of the code are selected for further analysis and decoding.

Subsequently, the size of the code matrix is obtained based on the two-dimensional code, thus, it is possible to calculate the coordinates of the data cell in the code matrix. Then, a judgment is made on whether each data cell is “0” or “1” (ie, light or dark), and each of these cells is converted to symbolic information.

For example, in JP application No. H 0212579 (IPC G06K 1/12; G06K 19/00; G06K 19/06; G06K 7/10; G06K 7/14, published. 1990-01-17), which is an analogue of the application of US patent No. 4939354, describes a matrix consisting of sequentially arranged dark (black) squares and two dotted sides, consisting of alternately light (white) and dark squares. Symbology is detected by distinguishing the line profile, and then determining the orientation of the matrix. The disadvantage of the above method is the following. The matrix is not always constant in size, so an error can occur in cell detection when the cell position is predicted according to a given interval. In addition, there is the possibility that, in exactly the same way as the characteristics of the four peripheral sides, an error may occur in the reading in the data area. This will require complex processing for the matrix read operation. Accordingly, such a complex read operation will require a significantly longer time, which will make automatic reading and decoding more difficult.

The invention is known WO 2013/100794 A1 is known to use an ultra-compressed code - nanobar code (abstract, paragraph 9 of the formula). The coding system specified in the invention is used to encode only text information in the formation of information fields and provides for the possibility of changing the code more than 10 ⁷⁰⁶ times. The disadvantage of this method is the lack of the ability to encode any digital information except text. In addition, there are no mechanisms for data compression and recovery of lost information.

In the invention US 2003/0128140 A1 a method for compressing digital information is known. This invention provides methods for code compression and decompression architectures for embedded systems. The compression of information is based on optimal code methods, while the probabilities of occurrence of code words for each block of encoded information are calculated only for this block and then recounted for each block, the decompression of information is also based on the sum of the probabilities obtained at the stage of compression with the calculation of the probabilities of the source code words . A significant drawback of this method is the need to calculate the probability for all input elements, and thus require the calculation of the values of all elements of the array, which significantly increases the processing time and the likelihood of errors or loss of information during compression / decompression.

Known patent US 5224106 A, which proposes a method of information recovery, which consists in adding redundant information to recover in case of loss and restoring lost information using information recovery algorithms based on redundant information recorded during code formation. To generate excess information, a polynomial of the form g ₂ (x) = (x + α ^ad ) * (x + α ^{a-d + 1} ) * ... * (x + α ^a ) * ... * (x + α ^{a + s} ) is used * (x + α ^{a + s + 1} ) * ... * (x + α ^{a + s + d} ). The disadvantages of the proposed method include the need to calculate separate mapping tables for each of the operations of the data recovery algorithm, as well as the use of two different polynomial expressions for their calculation. This complicates the solution of the factorization problem and increases the number of enumeration options required for key selection.

Thus, the existing methods for the formation of two-dimensional symbols only partially solve the problem of unambiguous identification and confirmation of the authenticity of the product or object.

To protect information, known methods of information protection based on the use of cryptographic algorithms can be used. Such methods include the conversion of information using cryptographic functions and algorithms, but, in the vast majority do not provide a variant of machine-readable two-dimensional symbols.

In the application for the invention RU No. 20011117145 (IPC G06F 12/14, published. 06/10/2003) a security method is proposed based on the formation of a key, which is stored in the memory of an external device, adapted for connecting to a computer, decrypting information using the key in an external device at the same time, the key is generated directly in the external device, and information is encrypted using the key in the same device. The key formation is carried out using pseudo-random sequence signals and signals of external random action, followed by an automatic check of the key for the absence of matches with keys stored in the memory of an external device. The key is stored in the memory of an external device adapted for connecting to a computer, decrypting information using a key in an external device, characterized in that the key is generated during the exchange of information between subscribers in the external device of one of the subscribers, encrypted with a system key previously stored in memory system key of all devices of subscribers of one series, and transfer the encrypted key to another subscriber, decrypt it from another subscriber, while the encryption of information is carried out vlyayut using the key in the external device, each of the subscribers.

The disadvantages of this method include the lack of the possibility of implementing the method in the event of force majeure, such as damage to the equipment of the user or failure of the equipment segments. Also, the specified method uses a control sequence (key), which is either shorter or corresponds to the length of the message and there is no exact estimate for the probability of imposing false information, thus increasing the likelihood of hacking or calculating a workaround to decrypt the protected information. Also, there is no embodiment in a graphic machine-readable form of a two-dimensional code.

Patent RU No. 2254685 (IPC H04L 9/00, published. 06/20/2005) describes a method of encrypting information conversion. Before encryption, all possible non-repeating values of combinations of the alphabet ui are randomly written using a random number sensor (RNG) into a code table with N lines, and each line ui of the address table Ta contains the number of line i of the code table Tk, in which the value of the alphabet combination ui, where N is the size of the alphabet that matches the number of lines of the code and address tables Tk and Ta, ui is the original combination to be encrypted. To fill in the next i-th line of the code table Tk, where i is a value from 1 to N, get the next value of the alphabet combination from the DSL, which is compared with each i-1 value of the recorded alphabet combinations in the code table Tk, and in case of mismatch with one of the recorded alphabet combinations, the next value of the alphabet combination ui is written in the i-th line of the code table Tk. When encrypting, from the string ui of the address table Ta, the address A (ui) of the original combination ui in the code table Tk is read, the value of the encrypted combination vi of the original combination of the alphabet ui with the value of the conversion parameter ξ _i is equal to the value of the alphabet combination stored in the string A (v _i ) of the code table Tk, whose address is defined as A (v _i ) = A (u _i ) + ξ _i modulo the number N, read the value of the encrypted combination v _i from the line of the code table Tk with the address A (v _i ), when decrypting the encrypted combination v _i for the parameter value conversion Define ξ _i t value combinations stored in the row address of A (u _i) of the code table Tc whose address is defined as _{A (u i) = A (} v i) -ξ i modulo the number N, and u _i is read the value combinations of the codebook row Tk with address A (u _i ).

The known method does not provide for the possibility of implementing the method in the event of force majeure, such as a breakdown of equipment at the user or failure of equipment segments. In addition, this method may provide for encoding only at the byte level, and also does not provide for the execution of a two-dimensional code in a graphic machine-readable form.

Known international application WO 2013162402 (IPC G06F 21/60; H03M 7/00, published. 10.31.2013) "Method of protecting digital information." In the known method, it is proposed to use cryptographic algorithms to protect information in the formation of the information field. However, the known method of encoding protected information does not allow to form a template for the location of the converted information on the matrix field and, accordingly, excludes the possibility of automated reading and decoding of information.

The known method is based on the principle of forming a system of encodings from a set of "0" and "1", it being assumed that "1" indicates the presence of a contrasting cell from the background, and "0" indicates the absence of a cell. Any bit information can be encoded using Latin characters, numbers, punctuation marks, national fonts, pseudo-graphic characters, etc., representing in general an array of characters. Any character from the encoding array can be represented as a multi-bit combination of “0” and “1”. For example, you can use an eight-bit character encoding system, i.e. it will look like this: 00000000, 00000001, 00000010, etc. A set of coding values is formed from a general and a private set of values; the formation in this system occurs with an equally probable choice of sets without the predominance of one of them. Moreover, the formation of arrays occurs independently of each other, and the cryptographic function is the source of the formation of the random number generator. The principle of information security is as follows. There is a message consisting of n characters (a1, b1, ... z1) and containing m repetitions of characters (a1, a2 ... am). There are a number of sets Ai equal to Q, assignment to message symbols (a1, b1, ... z1), randomly encoding values from Ai of the set, where i belongs to the set (1 ... Q). The correspondence of code values to symbols in the aggregates (A1 ... Ai) occurs randomly. The first character a1 is randomly assigned a value from the set Ai. The symbol an is assigned a value from the set Ai-1, and the selection from the range (A1 ... Ai) is also random. By analogy, the values are assigned to the remaining characters (b1, c1 ... z1). At the same time, one and the same character an in different parts of the message can be assigned a value from the set A1 β times, the number of β times the repetition of the characters an is also determined randomly.

The known method offers a method of protecting information, a method for its conversion during encoding and encryption, and also offers some graphic image of the generated nanobar code. However, such an image of a nanobar code does not allow standardizing its matrix and suggesting machine methods for reading and decoding it. In addition, the algorithm for the formation of the prototype does not provide for the formation of redundant information that allows you to restore lost information.

Also, patent RU No. 22251734 is known, "Machine-readable code, a method and apparatus for encoding and decoding" (IPC G06K 9/18, G06K 7/10, G06K 19/06, G06K 1/12, published. 05/10/2005), which together its essential features is the closest to the proposed invention, and adopted as a prototype. The known invention relates to the encoding of data with their presentation in the form of code using the layout of cells with different colors, shapes or configurations. The method includes the following: setting the code conversion table, setting the required data, encoding the required data, setting the parity area, and receiving the image in the form of a physical or electronic code.

The main advantages of the invention, in comparison with the prototype: the correlation of compactness with capacity; increased resistance to information corruption; the ability to recover more information; the ability to encrypt information; many options for implementation. The main difference of the invention in comparison with the prototype is the encoding method using a polynomial fundamentally different from the prototype.

In addition, there is the possibility of data recovery, there are supporting elements in the code structure for recognition and alignment of information. Information is encrypted with the ability to be applied to any surface.

Thus, the main objective of the present invention is to develop a method of encoding and decoding digital information in the form of an ultra-compressed nanobar code, with the ability to encrypt information that is resistant to damage and has many options for implementation.

The implementation of the nanobar code can be performed by various methods:

- the nanobar code can be visualized in the form of an image composed of light and dark cells, the standard are two-dimensional codes, for example, a QR code;

- the nanobar code can be represented as an array (stream) of protected data (the Crypto C information protection system is an analog);

- the nanobar code can be visualized in the form of coordinates and, thus, can be embedded in the application algorithm for various output devices;

- the nanobar code can be represented in the form of a control file that includes the data recording area and algorithms or commands that control the device for visualization (printer, laser installation, etc.);

- nanobar code can be implemented as an executable computer file.

The technical result achieved by using the proposed methods is to increase the reliability of information encoding by introducing an encryption operation, the possibility of recovering data in case of loss, as well as expanding the functionality.

The main advantages of the invention, in its practical application, in comparison with known methods:

- multi-platform encoding and decoding software;

- correlation of compactness with capacity;

- the nanobar code is more resistant to information damage;

- the ability to recover more information lost;

- the ability to encrypt information;

- many options for implementation.

In addition, the combination of constant and combinable elements allows the use of a nanobar code in various fields.

To read the nanobar code, its own unique hardware-software system for reading and recognition is used, which allows you to capture images in a wide range (from 0.05 to 100 mm).

An example of the implementation of a nanobar code in the form of a contrast image can be:

1) Printing

2) Laser marking (engraving)

Modern polygraphic digital printing allows you to reproduce high-definition and contrast images with a resolution of up to 2880 dpi, which meets any of the features of applying the specified geometric dimensions of the nanobar code. This method is suitable for placing a nanobar code on paper (documents), labels, packaging and other intermediate media.

To place the nanobar code directly on the material of the product or protected intermediate media (non-removable labels), it is recommended to use precision Laser Marking Complexes (LMK) or similar installations based on various lasers designed for applying text and graphic images to the surface of products using laser marking and engraving with high accuracy and resolution with the ability to integrate into production lines for working in automatic mode. Materials recommended for processing by laser radiation to reproduce the nanobar code include various metals and alloys (including hard ones), plastics, polymeric materials, and marking of wood, paper, fabric, leather, and plexiglass is also possible.

The technical result is achieved in that in a method for encoding digital information in the form of an ultra-compressed nanobar code, including receiving information to be encoded, encoding information using a code conversion table, and receiving a code message on an information carrier in the form of a physical or electronic code, according to the invention, after encoding Information is encrypted, compressed, and redundant information is added for recovery in case of loss.

Information is encrypted using cryptographic algorithms in two stages, at the first stage, encryption is carried out at the byte level using a polyalphabetic byte cipher with a different shift value for each information byte, at the second stage, encryption is performed at the bit level based on the AES symmetric encryption algorithm.

Compression of information is carried out on the basis of optimal code methods, and the probabilities of the occurrence of code words for each block of encoded information are calculated only for this block and recounted for each block, to generate a code message, the structure of the encoded data is formed.

Additional differences of the proposed method is the following. The number of mixing rounds during encryption at the byte level is 1, the received sequence of the encrypted message is translated into a hexadecimal number system and transmitted to the second bit encryption stage. For the first stage of encryption, a table of values of 256 by 256 characters or 256 tables of 256 positions is used, while the number of fields in the table corresponds to the number of fields in the ASCII coding table. At the second stage of encryption (bit encryption), the number of mixing rounds is finite and equal to q, while the message P of length a of characters is divided into the nth number of blocks of m characters in the block and is encrypted with an algorithm containing q mixing rounds. When encrypting at the bit level, all encryption rounds carry out a change in the design of the cipher, namely, between the Shift-Rows and MixColumns operations, blocks are shifted, while maintaining the mechanism for generating round keys and mixing steps.

In this case, the structure of the encoded data is formed in the form of a physical or electronic image of a two-dimensional code containing a background region, a region of orienting elements and a data region consisting of at least one data block, the image of the regions of the orienting elements and the data region being contrasted to the image of the background area. The orientation element area contains a reference square with a frame and an empty field, alignment rectangles and a code border frame. The data area containing the code message is superimposed on the area of the orienting elements so that the elements of the areas do not overlap each other. Any inscription and / or image can be placed inside the reference square, and the dimensions of the reference square, frame and empty field can be changed in different directions. The center of the reference square is located at the intersection of the symmetry axes of the alignment rectangles.

Also, the structure of the encoded data can be formed as a physical or electronic image of a set of coordinates on the coordinate plane.

In a second embodiment of the proposed method for encoding digital information in the form of an ultra-compressed code — a nanobar code, including receiving information to be encoded, encoding information using a code conversion table, and receiving a code message on an information medium in the form of a physical or electronic code, it is proposed to carry out the information after encoding its compression and the addition of redundant information for recovery in case of loss.

Information compression is proposed to be carried out on the basis of optimal code methods, and the probability of occurrence of code words for each block of encoded information should be calculated only for this block and recounted for each block to generate a coded data structure.

In this case, the structure of the encoded data is formed in the form of a physical or electronic image of a two-dimensional code containing a background region, a region of orienting elements and a data region consisting of at least one data block, the image of the regions of the orienting elements and the data region being contrasted to the image of the background area. The orientation element area contains a reference square with a frame and an empty field, alignment rectangles and a code border frame. The data area containing the code message is superimposed on the area of the orienting elements so that the elements of the areas do not overlap each other. Any inscription and / or image can be placed inside the reference square, and the dimensions of the reference square, frame and empty field can be changed in different directions. The center of the reference square is located at the intersection of the symmetry axes of the alignment rectangles.

Also, the structure of the encoded data can be formed as a physical or electronic image of a set of coordinates on the coordinate plane.

The technical result is also achieved by the fact that in the method of decoding digital information in the form of an ultra-compressed code, including reading the encoded data from the code, selecting useful information, decompressing, decrypting and decoding this information using a code conversion table, according to the invention, information is decrypted using the inverse cryptographic conversion functions in two stages, at the first stage, decryption is carried out at the bit level based on a symmetric bit AES encryption algorithm. At the second stage, decryption is carried out at the byte level using a polyalphabetic byte cipher with a different shift value for each byte of information. Information decompression is carried out on the basis of optimal code methods, based on the sum of the obtained probabilities at the compression stage, with the calculation of the probabilities of the source code words. Lost information is restored using information recovery algorithms based on redundant information recorded during code generation.

The number of mixing rounds during decryption at the byte level is 1, the received sequence of the encrypted message is translated into a hexadecimal number system and transferred to the second bit decryption stage.

For decryption at the byte level, a table of values of 256 by 256 characters or 256 tables of 256 positions is used, while the number of fields in the table corresponds to the number of fields in the ASCII encoding table.

At the first stage of decryption (bit encryption), the number of mixing rounds is finite and equal to q, while the message P of length a of characters is divided into the nth number of blocks of m characters in the block and is decrypted with an algorithm containing q mixing rounds.

When decrypting at the bit level, all encryption rounds carry out changes in the cipher design, namely, between the ShiftRows and MixColumns operations, blocks are shifted, while maintaining the mechanism for generating round keys and mixing steps.

In the second embodiment of the method for decoding digital information in the form of an ultra-compressed code, including reading the encoded data from the code, selecting useful information, decompressing and decoding this information using a code conversion table, it is proposed to decompress the information based on optimal code methods, and the probabilities of the occurrence of code words for each block of decoded information to calculate only for this block. Recover lost information using information recovery algorithms based on redundant information recorded during code generation.

The essence of the invention is illustrated by the following figures:

FIG. 1, which shows a general view of the nanobar code, where:

1 - pointer to the number of cells and columns in the symbolism,

2 - frame reference square,

3 - field of code words,

4 - reference square,

5 - alignment rectangles,

6 - code border frame,

7 - an empty field;

8 - background;

FIG. 2, which shows a preferred embodiment of the reference square with the inscription;

FIG. 3, which shows a variant of the reference square without an inscription;

FIG. 4, which shows a general view of the alignment rectangle;

FIG. 5, which shows a general view of the position of the upper alignment rectangle between the symbol boundary and the information field;

FIG. 6, which shows an image of a nanobar code obtained with a rotation angle equal to α. Moreover, α is an arbitrary angle of rotation of the image of the nanobar code relative to the coordinate axes OX and OY. Used to adjust the code relative to the axes for the correct receipt of the data stream and further decoding.

FIG. 7, which shows the corrected angle of rotation of the symbols, relative to the axes OX and OY;

FIG. 8, which presents the probabilities of occurrence of characters of the Russian alphabet, excluding probabilities in a separate text;

FIG. 9, which shows a diagram of a second encryption step, based on a symmetric cipher;

FIG. 10, which shows the scheme for changing the transfer of information between the ShiftRows and MixColumns encryption functions (changing the design of the cipher compared to the similar symmetric AES cipher);

FIG. 11, where a message block and a key block are presented before the first round of the second encryption step;

FIG. 12, which shows the calculated values of the encrypted text of one block after various round operations of the encryption rounds (second to sixth);

FIG. 13, which shows the calculated values of the encrypted text of one block after various round operations of the encryption rounds (from the sixth to the tenth);

FIG. 14, which shows the calculated values for generating round keys from a common message key (from the first to the fourth rounds and in the tenth round);

FIG. 15, where the block binding mode in the SHS mode is shown (Cipher Block Chaining).

FIG. 16, which shows the general structure of a block with data and RS-code for error recovery, where:

n are parity characters,

k is the total length of a codeword including encoded data and parity symbols n. The number of parity characters is: n - k.

t is the maximum number of correctable errors,

2t is the total number of parity characters,

RS (n, k) is a certain kind of correction codes that operates with n-character blocks, k-characters of which represent useful data, and all others are reserved for parity characters;

FIG. 17, where a polynomial of 120 characters is represented (for blocks 256 bytes long).

FIG. 18, which shows the sizes of the nanobar code, depending on the number of characters (the number of characters from one to 2000);

FIG. 19, where a fragment of a nanobar code is presented, in the form of coordinates of the centers of the modules;

FIG. 20, which shows decryption in SHS mode;

FIG. 21, which shows the data structure of one message block.

FIG. 22, which shows a general view of a nanobar code with various sizes of orienting and code blocks.

FIG. 23, which shows the location of the origin on the coordinate plane in its center;

FIG. 24, which shows a variant with the location of the origin in any area of the coordinate plane;

FIG. 25, which shows the filled coordinate plane.

The symbol of the proposed code (nanobar code) is located on the background 8 (Fig. 1) and is composed of graphic elements representing a unit square or elementary code module. Moreover, the size of the elementary code module can be dimensionally equal to the selected resolution (dpi) of symbolic formation or proportional to the resolution of the symbolic.

In FIG. 2, the reference square 4 (Fig. 1) is a field bounded by a frame 2 around the perimeter, at least two modules thick and an empty field 7, in which there may be an inscription. In addition to the inscription, the reference square 4 may contain an image representing a raster monochrome, polychrome or graphic object made in grayscale, for example, a logo. The resolution of such a graphic object corresponds to the resolution of the proposed symbology, while the elementary code module is proportional to one pixel of the graphic object. The dimensions of the object are calculated based on the minimum size of the reference square 4 with the inscription. A color graphic image can consist of shades of a standard palette, attributes can be assigned to a graphic object. The specified graphic object does not affect the readability and decoding of the information contained in the nanobar code, but at the same time carries an additional expert attribute of the authenticity of both the symbol itself and the object on which it is applied. The minimum size of the reference square 4 containing the inscription along the outer perimeter is 25 × 25 modules, and at least 10 × 10 modules without the inscription.

The central reference square can be represented as a square enclosed in a square frame, while the dividing white frame has a thickness of at least four modules (Fig. 3). The sizes of the elements of the reference square 4 may take various sizes. Below are the minimum sizes:

central square - 2 × 2 modules,

the white field surrounding the central square - 8 × 8 modules,

the external dimensions of the black frame surrounding the central square and the empty field are 12 × 12 modules (with a frame thickness of two modules).

The dimensions of the central square, frame 2, empty field 7 may vary in different directions. The reference squares are located at the intersection of the axes of symmetry of the symbolism and do not move in the symbolism field.

.Alignment rectangles (Fig. 4) are designed to align the code when shooting relative to the X and Y axes (Fig. 6 and Fig. 7). The size of the rectangle is equal to the code module. The minimum dimensions of a 1 × 2 rectangle are modules. The dimensions of the rectangle may vary depending on the size of the code and the ratio of its elements. The recommended aspect ratio of alignment rectangles is

.

The alignment rectangles 5 (Fig. 1) are located on a white field located between the boundary of the symbol area and the data area. The white box has a minimum width of three modules. The width of the field can vary, depending on the size of the symbolism and the relations of its supporting elements. The alignment of horizontal alignment rectangles on the horizontal axis may deviate from the central vertical line of symmetry and shift throughout the empty field along the horizontal plane of movement. The minimum number of alignment rectangles on each side of the symbolism is 1. Depending on the amount of information and the size of the symbolism, the number of alignment rectangles may vary.

The mapping of the nanobar code can be implemented as follows:

visualized in the form of an image composed of light and dark cells (elementary modules), the standard are two-dimensional codes, for example, a QR code;

It is presented in the form of an array (stream) of protected data (the Crypto C information protection system is an analog);

visualized in the form of coordinates of the centers of elementary modules;

presented in the form of a control file that includes a data recording area and control algorithms for visualization (printer, laser installation, etc.) algorithms or commands;

implemented as an executable computer file.

An example of the implementation of the nanobar code in the form of coordinates (a fragment of the coordinate plane) is presented in table 1.

A 256-character ASCII table is used to encode symbolic information — to convert character information to a decimal or hexadecimal number system for further processing by the encryption algorithm, where each character of the encoded message is mapped to the position number of this character in the ASCII table. The first half of the international format ASCII table is used, from 0 to 127 characters. The second half of the ASCII table contains Cyrillic characters and pseudographics of the place from 128-256.

After encryption, the data is compressed by an algorithm based on the method of using optimal codes, with the difference that the probabilities for each incoming message are calculated only for this message. Those. there are probabilities of occurrence of letters of the Russian alphabet, defined on many texts, but in a sample of texts consisting of one text, the probabilities of occurrence of letters may differ from all the certain probability on a larger set of text. For the most optimal compression, the probabilities must be recounted for each message. In general, the probability of occurrence of an element s _i is equal to p (s _i ), the representation of this element will be - log ₂ p (s _i ) bits. If during encoding the length of all elements is reduced to log ₂ p (s _i ) bits, then the length of the entire encoded sequence will be minimal for all possible encoding methods. Moreover, if the probability distribution of all elements F = {p (si)} is unchanged, and the probabilities of the elements are mutually independent, the average length of the codes can be calculated as:

H = −Σ _i p (s _i ) ⋅log ₂ p (s _i ).

The value of H is the entropy of the probability distribution F, or the entropy of the source at a given point in time. However, the probability of the appearance of an element cannot be independent; on the contrary, it depends on various factors. In this case, for each new encoded element s _i, the probability distribution F will take some value F _k , that is, for each element F = F _k and H = H _k .

In other words, we can say that the source is in state k, which corresponds to a certain set of probabilities p _k (s _i ) for all elements s _i . Given this, the average code length can be calculated by the formula:

H = -Σ _k P _k ⋅ H _k = -Σ _{k, i} P _k ⋅p _k (s _i ) log ₂ p _k (s _i ).

where P _k is the probability of finding the source in state k.

In FIG. Figure 8 shows the probabilities of occurrence of symbols of the Russian alphabet, without taking probabilities into account in a separate text.

Definition of a sequence of code values

Similarly, binary data is encoded, with the difference that a codeword table is built for each message. The probability of the received code words in the message is calculated. To obtain uniquely decoded optimal codes, prefix codes are used. The prefex codewords are determined from the binary graph, and the message is recoded to obtain the optimal code length. Table 2 presents the possibility of encoding the words A1-A4 with different bit sequence lengths.

Text Encryption

The encryption method used in the nanobar code is a block symmetric encryption algorithm. The encryption block provides encryption at the first stage at the level of bytes (characters), and at the second stage at the level of bits. In the first encryption step, at the byte level, the number of mixing rounds is set to 1. At the second encryption step, at the bit level, the number of mixing rounds is provided, with a finite number of rounds equal to q. A message P of length a of characters is divided into the nth number of blocks, with a volume of m characters in a block, and encrypted with an algorithm containing q rounds of mixing. For the first stage of encryption at the byte level, a table of values of 256 * 256 characters (256 tables of 256 positions) is used, while the number of fields in the table corresponds to the number of fields in the ASCII coding table.

Formulas are used to encode a character message:

Ci≡Pi + Ki (mod 256), where:

P = P ₁ P ₂ P ₃ ... - code words of the message

C = C ₁ C ₂ C ₃ ... - received message values

k = [(k ₁ , k ₂ ), (k ₃ , k ₄ ), ... (k _n , k _m )] - stream keys

The key stream is independent of the characters in the source text, it depends only on the position of the character in the source text. In other words, a key stream can be created without knowing the essence of the source text.

For example, encode the source text for "Sheis listening":

Let's choose a key stream generator - the keyword "PASCAL".

The full key stream is equal to the length of the message:

(112, 97, 115, 99, 97, 108, 112, 97, 115, 99, 97, 108, 112, 97).

The stream of values of the encrypted message:

(217, 201, 216, 204, 213, 216, 217, 213, 231, 200, 207, 213, 222, 200)

Stream in hexadecimal notation:

(C9, D8, CC, D5, D8, D9, C9, D5, E7, C8, CF, D5, DE, C8)

For ease of perception, we summarize the data in table 3.

The second stage of encryption is based on the symmetric AES bit encryption algorithm (Fig. 9) with cipher design changes: between the ShiftRows and MixColumns operations, blocks are shifted, while the mechanism for generating round keys and mixing steps is preserved (Fig. 10). The shift of blocks between the ShiftRows and MixColumns operations allows to increase the cryptographic stability of the algorithm. Evaluation of the increase in cryptostability without bias 2 ⁿ operations, with bias (2 ⁿ )! operations.

The SubBytes operation is a tabular replacement of each byte of the data array, according to the following data. Those. input sequence values are replaced with the corresponding table values. The values of the table are calculated on the basis of known polynomials giving an equiprobable distribution of characters after the operation (Table 4).

Thus, when coding based on AES, and performing the SubBytes operation, bijective mapping occurs using the table generated using the polynomial xn + xn-1 + ... + 1 = 0, where n∈P (P is the space of primes). In this case, the data array of the substitution is equal to the values from a ₁ to r ₁₆ , where n∈P (P is the space of primes). In addition, in the case of encryption, as in the case of encoding, there is a bijective mapping of elements of one alphabet to another (from alphabet A to alphabet B) with the difference that during encryption, the mapping function (key) is unknown. In the present invention, mapping during encoding occurs using the well-known ASCII encoding table, when encrypting using a table formed using the polynomial xn + xn-1 + ... + 1 = 0. So, it is possible to use both concepts, indicating the table used.

The ShiftRows operation rotates to the left all rows of the data array, with the exception of zero. The shift of the ith row of the array (for i = 1, 2, 3) is performed by i bytes.

In this case, the shift can occur both multiplicatively and additively, moreover, with a shift both to the left and to the right side along the data array. Those. the data sequence can not only add up to the generated pseudo-random sequence, but also be subtracted and also multiplied. In this case, the calculation (search) of the element lying in the field 0-255 can occur both from smaller values to large, and from large to smaller values. This allows you to optimize the search function of the remainder of the result of addition or multiplication.

The MixColumns operation multiplies each column of the data array, which is considered as a polynomial in the final field GF (2 ⁸ ) by a fixed polynomial a (x): a (x) = 3x ³ + x ² + x + 2.

Multiplication is performed modulo x ⁴ +1.

The AddRoundKey operation superimposes the key material onto the data array, namely, on the ith column of the data array (i = 0 ... 3), the bitwise logical operation “exclusive or” (XOR) superimposes a certain extended key word W _{4r + i} , where r - the number of the current round of the algorithm starting from 1 (the procedure for expanding the key will be described below).

The number of rounds of the algorithm R depends on the size of the key, the dependence is presented in table. 5.

Before the first round of the algorithm, the key material is preliminarily overlaid using the AddRoundKey operation, which superimposes the first four words of the extended key W ₀ ... W ₃ on the plaintext.

The last round differs from the previous ones in that the MixColumns operation is not performed in it.

The number of possible rounds of encryption of block sizes and key sizes is presented in Table. 6.

Key extension: the algorithm uses encryption keys of three fixed sizes: 128, 192, and 256 bits. The task of the key extension procedure is to generate the required number of words of the extended key for their use in the AddRoundKey operation. By “word” here is meant a 4-byte fragment of the extended key, one of which is used in the primary overlay of the key material and one in each round of the algorithm. Thus, in the process of key expansion, 4 * (R + 1) words are formed. The extension of the key is carried out in two stages, the first of which initializes the words of the extended key (denoted by W _i ): the first Nk (Nk is the size of the original encryption key K in words, i.e. 4, 6 or 8) of the words W _i ( i.e. i = 0 ... Nk-1) are formed by their sequential filling in bytes of the key.

For example, we will encrypt a data block of size 128 using ten rounds of encryption and a key size of 128 bits.

Message:

Message Key:

The message stream after the first encryption step enters the blocks together with the key stream (Fig. 11). In each round of encryption, the message is converted and takes the form shown in FIG. 12 and 13.

As a result, at the output, the sequence of the encrypted message looks like:

At each stage of encryption, round keys are generated from a common stream key (Fig. 14).

An example of the formation of round keys.

In FIG. 14 shows the calculated round keys for the message flow presented above. Here, as in the case of the byte encryption step, the key length is equal to the message length. The total number of encryption rounds is eleven (including the first step). The key for the byte and bit encryption blocks is generated by the user - by entering a code sequence of characters. At the same time, the length of the stream key is formed equal to the length of the original message.

The CBC mode (Cipher Block Chaining) is shown in FIG. 15. Each block of plaintext is added bitwise modulo two with the previous encryption result.

In general, encryption can be described as follows:

C ₀ = IV

C _i = E _k (P _i ⊕C _i-1 )

where i are the block numbers, IV is the initialization vector, C _i and P _i are the blocks of the encrypted and plaintext, respectively, and E _k is the block encryption function.

The number of clutch blocks is equal to the number of ciphertext blocks obtained after the encryption step. The plaintext passed through the XOR encryption block with the initialization vector gives the ciphertext, which is the input to the next clutch block. The initialization vector is indicated only for the first clutch block.

Error Detection and Correction Procedure

To detect errors, a special case of BHC codes is used (Bowes-Chowdhury-Hockingham codes). In coding theory, this is a wide class of cyclic codes used to protect information from errors), with an error recovery level of up to 40% of the lost information (Fig. 16).

The formation of redundant information occurs using the polynomial x ⁿ + x ^n-1 + ... + 1 = 0, where n∈P (P is the space of primes). In this case, the polynomial used is universal, both for the SubBytes operation and for generating redundant information.

The preferred algorithm for generating redundant information consists of the following steps:

1) k zeros are added to the original information word D to the right, we get a word of length n = m + r and a polynomial Xr * D, where m is the length of the information word;)

2) The polynomial Xr * D is divided by the generating polynomial G, and the remainder of the division R is calculated such that: Xr * D = G * Q + R, where Q is the quotient that is discarded.

3) The remainder R is added to the information word D, a code word C is obtained, the information bits of which are stored separately from the control bits. The remainder resulting from the division is a correction code.

4) The information word + correction codes can be written as follows: T = Xr * D + R = GQ. It is worth noting that all operations are performed in the final Galois fields GF (2 ⁿ ).

The encoded data is transmitted through the data [i] array, where i = 0 ... (k-1), and the generated parity characters are entered into the array b [0] ... b [2 * t-1]. The source and resulting data are presented in polynomial form. Encoding is performed using a shift feedback register filled with the corresponding array elements with the generated polynomial inside.

c (x) = data (x) * x (n-k) + b (x).

Formula of a generating polynomial for generating direct and inverse GF (2 ⁿ ):

x ^ 8 + x ^ 4 + x ^ 3 + x ^ 2 + 1.

A polynomial of dimension 120 (for blocks of length 256), which allows recovering up to 120 errors in a block (Fig. 17).

In addition, when compressing information, probabilistic methods are used to determine the output value of the data based on determining the effective monotonic scheme for the voting function. Those. the calculation of probabilities occurs only for the elements of the input sequence on which the monotonic function is built, the remaining elements of the sequence are obtained by translating the previously obtained elements. This allows not to calculate the probabilities for all input elements and optimizes the procedure.

Code sizes vary depending on the amount of encoded data. The minimum size of symbols, when encoding one symbol does not change in the range from 1 to 100 characters. The minimum size of the symbology is 14, the upper value depends on the amount of information encoded in the code.

FIG. 18 shows the sizes of the nanobar code, depending on the number of characters.

The nanobar code can be technically implemented, both in graphic format, in the form of a raster or vector image, and in the form of a control file. The control file contains the coordinates of the location of the cells, relative to the center of symbolism, and the coordinates of the vector objects (Fig. 1, Fig. 4,), as well as the technical parameters of the material processing by this technology using this equipment. As an example, the parameters of a laser pulse installation are given.

When forming a nanobar code, it should be borne in mind that the recommended sequence of actions is as follows:

- Coding and translation of information from a binary form;

- encryption;

- Archiving;

- Adding redundant information to restore lost data;

- Location on the field of symbolism.

When changing the order of the function, the optimal ratio between the amount of encoded (encrypted) information and the possibility of complete data recovery is not guaranteed.

It is recommended that the information recovery function be performed last, in any other case, correct information recovery, in case of partial distortion is not guaranteed.

Also, it should be noted that the formation of a nanobar code using the proposed method provides for the formation of a nanobar code in a "closed" and "open" form. The formation of a “closed” nanobar code has the above sequence of actions. When generating an “open” nanobar code, the preferred “Encryption” item can be excluded, and thus a two-dimensional machine-readable code is obtained, which is used in traditional logistics and identification schemes that do not provide for special information protection.

In addition, one should take into account restrictions on the amount of encoded and encrypted information placed in the nanobar code, this is due to the advisability of using the nanobar code, in one case or another. Thus, the maximum information content of the proposed nanobar code is ensured, as well as the ability to create “closed” or “open” local databases associated with an object or product.

Recommended Decoding Method

To decode a nanobar code visualized as an image or applied to any material, it is read. In this case, a specialized unique hardware-software system for reading and recognition is used, which allows you to capture images in a wide range (from 0.05 to 100 mm) and convert it into a digital data stream. Further decoding is performed as follows.

In FIG. 20 shows the process of decrypting blocks encrypted in SHS mode. After, decryption is performed at the bit and byte levels, in general, the decryption process can be represented by three expressions:

where i are block numbers

C _i and P _i - blocks of encrypted and plaintext, respectively

D _k - function dependent on the input block C _i

E _k - block encryption function

E ^k-1 is the inverse function of the block encryption function

K - stream keys

K _i - i-th stream key

P - message code words

(mod 256) - integer remainder of division by 256

The structure of the transmitted data

The structure of the symbol, which includes a field with recording information, including the recording area, which consists of blocks, a separate block contains service information, 4 bytes - the length of the code (Fig. 21).

When using the graphic image format, the following data is transmitted:

- Cypher (1 byte) - type of encryption (1 - without encryption, 2 - encryption);

- Extension (string) - extension of the source file.

When using the control file format, the following data is transferred:

- Device (string) (device for outputting a nanobar code);

- Material (string) (data on the material on which the nanobar code is applied);

- Cypher (1 byte) - type of encryption (1 - without encryption, 2 - AES encryption);

- Extension (string) - extension of the source file.

Thus, the proposed method allows to form as a closed, i.e. with encoded and encrypted information, and open, i.e. only with encoded information nanobar code.

Advantages of the proposed nanobar code:

uses two levels of encoding (before and after encryption), as well as a unique way of arranging unit cells (location of information blocks), which allows you to compress information in comparison with known codes.

When comparing with the QR-Code, with a large amount of encoded information (in the example, the maximum size of the QR-Code) for the nanobar code, the advantage in the field of useful information is obvious (see table 7).

The QR-code (like others) has a fixed position of auxiliary information, system information is duplicated, and in case of loss of both blocks of service information, it is impossible to decode the code.

In the nanobar code, service information is in each separate block; there are no separate markers on them. With the loss of recovery information in a block, the entire message does not lose, information is not restored only in this block.

An additional advantage of the nanobar code is the correlation of the compactness of the code with its capacity. That is, the more information the nanobar code contains, the more dense (ultradense) it becomes. In addition, the fixed dimensions of the orienting elements during decoding allow:

- accurately determine the position of the block with useful information;

- determine the multiplicity of rows and columns of cells (modules) for the unique formation of the data array.

Thus, the nanobar code is more resistant to damage to areas of service information. It should also be noted that the information recovery algorithms used in the formation of the nanobar code are better, because 40% of lost information can be restored, while QR-Code and Data Matrix recover only 35%.

An advantage of the proposed methods is the use of high-level data encoding, in which information processed by encryption algorithms is compressed by the optimal code method, while the probabilities for each incoming message are calculated only for this message (i.e., there are probabilities of occurrence of letters of the Russian alphabet defined on many texts, but in a sample of texts consisting of one text, the probabilities of occurrence of letters may differ from all the certain probability by a larger number of payback text.).

The advantage of using digital information encryption in the proposed method: encryption at the first stage occurs at the level of bytes (characters), at the second stage at the level of bits. In addition, the second stage of encryption is based on the AES symmetric bit encryption algorithm with cipher design changes: between the ShiftRows and MixColumns operations, blocks are shifted, while the mechanism for generating round keys and mixing stages is preserved, which allows to increase the cryptographic strength of the method.

Claims (36)

1. A method of encoding digital information in the form of an ultra-compressed code — a nanobar code, including receiving information to be encoded, encoding information using a code conversion table, and receiving a code message on an information medium in the form of a physical or electronic code, characterized in that after encoding the information, it is encrypted, compressed and added redundant information to be restored in case of loss, - information is encrypted using cryptographic algorithms in two stages, at the first stage, encryption is carried out at the byte level using a polyalphabetic byte cipher with a different shift value for each byte of information, at the second stage, encryption is performed at the bit level based on the AES symmetric encryption algorithm, - information compression is carried out on the basis of optimal code methods, and the probability of occurrence of code words for each block of encoded information is calculated only for this block and recounted for each block, - to obtain a code message, the structure of the encoded data is formed in the form of an ultra-compressed nanobar code. 2. The method according to p. 1, characterized in that the number of mixing rounds during encryption at the byte level is 1, the received sequence of the encrypted message is translated into a hexadecimal number system and transmitted to the second bit encryption stage. 3. The method according to claim 2, characterized in that for the first stage of encryption, a table of values of 256 by 256 characters or 256 tables of 256 positions is used, while the number of fields in the table corresponds to the number of fields in the ASCII encoding table. 4. The method according to p. 3, characterized in that at the second stage of encryption (bit encryption) the number of mixing rounds is finite and equal to q, while the message P of length a of characters is divided into the nth number of blocks of volume m characters in the block and is encrypted with an algorithm containing q rounds of mixing. 5. The method according to p. 4, characterized in that when encrypting at the bit level on all encryption rounds, the cipher design is changed, namely, between the ShiftRows and MixColumns operations, blocks are shifted while maintaining the mechanism for generating round keys and mixing steps. 6. The method according to p. 5, characterized in that the structure of the encoded data is formed in the form of a physical or electronic image of a two-dimensional code containing a background region, a region of orienting elements and a data region consisting of at least one data block, the image of the regions orientation elements and data areas are contrasting with the image of the background area, - the area of the orienting elements contains a reference square with a frame and an empty field, aligning rectangles and a border frame of the code, - the data area containing the code message is superimposed on the area of the orienting elements so that the elements of the areas do not overlap each other. 7. The method according to p. 6, characterized in that any inscription and / or image can be placed inside the reference square, and the dimensions of the reference square, frame and empty field can be changed in different directions. 8. The method according to p. 7, characterized in that the center of the reference square is located at the intersection of the axis of symmetry of the alignment rectangles. 9. The method according to p. 5, characterized in that they form the structure of the encoded data in the form of a physical or electronic image of a set of coordinates on the coordinate plane. 10. A method of encoding digital information in the form of an ultra-compressed code of a nanobar code, including receiving information to be encoded, encoding information using a code conversion table, and receiving a code message on an information medium in the form of a physical or electronic code, characterized in that after encoding the information, it is compressed and redundant information is added for recovery in case of loss, - information compression is carried out on the basis of optimal code methods, and the probability of occurrence of code words for each block of encoded information is calculated only for this block and recounted for each block, - to obtain a code message, the structure of the encoded data is formed in the form of an ultra-compressed nanobar code. 11. The method according to p. 10, characterized in that the structure of the encoded data is formed in the form of a physical or electronic image of a two-dimensional code containing a background region, a region of orientation elements and a data region consisting of at least one data block, the image of the regions orientation elements and data areas are contrasting with the image of the background area, - the area of the orienting elements contains a reference square with a frame and an empty field, aligning rectangles and a border frame of the code, - the data area containing the code message is superimposed on the area of the orienting elements so that the elements of the areas do not overlap each other. 12. The method according to p. 11, characterized in that any inscription and / or image can be placed inside the reference square, and the dimensions of the reference square, frame and empty field can be changed in different directions. 13. The method according to p. 12, characterized in that the center of the reference square is located at the intersection of the symmetry axes of the alignment rectangles. 14. The method according to p. 10, characterized in that they form the structure of the encoded data in the form of a physical or electronic image of a set of coordinates on the coordinate plane. 15. A method of decoding digital information in the form of an ultra-compressed code, including reading the encoded data from the code, selecting useful information, decompressing, decrypting and decoding this information using a code conversion table, characterized in that - information is decrypted using the inverse cryptographic conversion function in two stages, at the first stage, decryption is carried out at the bit level based on the AES symmetric bit encryption algorithm, at the second stage, decryption is performed at the byte level using a polyalphabetic byte cipher with a different shift value for each byte information - information decompression is carried out on the basis of optimal code methods based on the sum of the obtained probabilities at the stage of compression with the calculation of the probabilities of the source code words, - lost information is restored using information recovery algorithms based on redundant information recorded during code formation. 16. The method according to p. 15, characterized in that the number of mixing rounds during decryption at the byte level is 1, the received sequence of the encrypted message is translated into a 16-digit number system and transmitted to the second bit decryption stage. 17. The method according to p. 16, characterized in that for the second stage of decryption, a table of values of 256 by 256 characters or 256 tables of 256 positions is used, while the number of fields in the table corresponds to the number of fields in the ASCII coding table. 18. The method according to p. 17, characterized in that at the first stage of decryption (bit encryption) the number of mixing rounds is finite and equal to q, while the message P of length a of characters is divided into the nth number of blocks of volume m characters in the block and decrypted with an algorithm containing q rounds of mixing. 19. The method according to p. 18, characterized in that when decrypting on all decryption rounds at the bit level, the cipher design is changed, namely, between the ShiftRows and MixColumns operations, the blocks are shifted while maintaining the mechanism for generating round keys and mixing steps. 20. A method of decoding digital information in the form of an ultra-compressed code of a nanobar code, including reading the encoded data from the code, selecting useful information, decompressing and decoding this information using a code conversion table, characterized in that - decompression of information is carried out on the basis of optimal code methods, and the probability of occurrence of code words for each block of decoded information is calculated only for this block, - lost information is restored using information recovery algorithms based on redundant information recorded during code formation.

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