UA22215U - Method of cryptographic transformation of information - Google Patents

Abstract

The proposed method of cryptographic transformation of information consists in presenting the information sequence as 128-bit data blocks and performing the iterative processing of the data blocks by the corresponding units using simple operations of cryptographic transformation, such as an operation for substituting bytes according to the fixed byte replacement table, an operation for repeatedly shifting data rows by a specified number of bytes, an operation for mixing data columns, and an operation for adding a coding key. In performing the operation of adding a coding key, a variable function is used that is generated according to an iterative procedure, using the fourth-other matrix that is specified depending on the coding key.

Description

Description of the invention

The proposed useful model refers to the field of cryptographic protection of information and can be used in encryption tools in information processing systems to expand their capabilities.

There is a known method of cryptographic transformation ||, which is based on the fact that the information sequence is presented in the form of 64-bit blocks, which are subject to iterative processing by primitive cryptographic transformations: permutation (regtiiayop) - using permutation blocks (P-blocks); substitution (zirziyshiop) - with the help of substitution blocks (5-blocks); functional operations of cyclic shift and 70 addition of the key modulo 2 - with the help of appropriate devices. Iterative processing consists in multiple execution of the same groups of transformations, which provide the necessary conditions for the stability of the cryptographic transformation.

The disadvantage of this method is that a fixed function is used for the cryptographic transformation of information as a gamma function in the operation of bitwise addition of the key, which does not allow to flexibly change the 12 parameters of the cryptographic processing of information data.

The closest to the proposed technical solution, chosen as a prototype, is an improved method of cryptographic transformation |2), which is based on the fact that the information sequence is presented in the form of 128-bit blocks, which are subject to iterative processing by primitive cryptographic transformations: substitution (zirziysiop) of bytes ( ZyrVuiez) with a fixed substitution table of size 8x256 - using substitution blocks (5-blocks); functional operations of cyclic period shift (ЗпПШЩКОМ5) - byte-by-byte shift of the dates of the data array (biaie) by a distinct number of bytes; shuffling of columns (MixSoiYShtpv) - multiplication of columns of data, considered as polynomials over OK(2 8), by a polynomial of the third degree d(x) modulo x?-1 and addition of a round key (AdaKoshipakKeu) - by bitwise addition of the current round key using appropriate devices. Iterative processing consists in multiple execution of the same groups of transformations, which provide the necessary conditions for the stability of the cryptographic transformation. -

The disadvantage of the prototype method is that for the cryptographic transformation of information as a gamma function in the operation of bitwise addition of AdaKoshipKeu, a fixed function is used, which depends only on the current value of the round key, which does not allow to flexibly change the parameters of cryptographic processing of information data during execution round key addition operations.

The basis of a useful model is the task of creating a method of cryptographic transformation of information - which, due to the use of the variable c function as a gamma function in the operation of bitwise addition of the AdakKoypakKeu variable, will make it possible to flexibly change the parameters of the cryptographic processing of information data when performing the operation of adding a round key. with

The task is solved by using the variable gamma function (5) as the operation of adding the round key c (AdakoshipakKeu), which is formed according to an iterative rule using the variable quaternary matrix M of the fourth order, which is chosen according to the value of the round key.

Function C is a binary vector, the size of which coincides with the size of the block, and is composed according to the scheme « ; - sho a- ves» :z» de | is a concatenation sign, C, is a thirty-two-bit binary vector.

The vector Co is formed as a result of bit-by-bit addition modulo 2 of the current round key and co of the thirty-two-bit vector, which is formed by expanding the variable quaternary matrix M of the fourth order by concatenating the terms of the matrix. The matrix M is chosen according to the value of the cyclic key. o The vector O,, and- 1 Z is formed according to the expression ke ' - 70 a ! z s o, Shchi ist 9, where « 7 is a code combination formed from vector C) as a result of its cyclic shift by 7 digits c) to the left. c The technical result that can be obtained when implementing a useful model consists in obtaining the ability to flexibly change the parameters of cryptographic processing of information data when performing the operation of adding a round key.

The essence of the proposed method of cryptographic transformation of information lies in the fact that the information sequence is presented in the form of 128-bit blocks, which are subject to iterative processing by primitive cryptographic transformations: permutation (zirziyshiop) of bytes (ZibWaves) with a fixed table of substitutions with a dimension of 8x256 - with the help of permutation blocks (5 -blocks); functional operations of cyclic time shift (ZPKOM85) - byte-by-byte time shift of the data array (Ziaie) by a different number of bytes; shuffling of columns (MixSoYShtp5) - multiplication of data columns, considered as polynomials over ОК(28), by a polynomial of the third degree d(x) modulo x7--1 and addition of a round key (AdakKoshipakKeu) -

by bit-by-bit addition of the current round key and a thirty-two-bit vector formed by expanding the variable quaternary matrix M, which is chosen according to the value of the round key.

Iterative processing consists in multiple execution of the same groups of transformations, which provide the necessary conditions for the stability of the cryptographic transformation.

The proposed technical solution allows performing cryptographic transformation of data by flexibly changing the gamma function and dynamically controlling iterative processing of information data.

Thus, due to the use as a round key addition operation (AdaKoishpakKeu) of the variable gamma function (5), which is formed according to the iterative rule using the variable quaternary matrix M 7/0 of the Fourth order, which is chosen according to the value of the round key, it is possible to flexibly change parameters of cryptographic processing of information data when performing the operation of adding a round key.

Sources of information: 1. Maiyopa! Ipziyshe oi Ziapaagaz apa Tesppoiodu, RIRBZ-46-3: YuOaya Yeepsguriop B (apdaga Osi. 1999,

Aumayarie ai per://svgs.pivi dom/rybiisayopeLrv/ pEr://svgs.pivi dom/rybiiisabyoperae/Lirz46-ZLirz46-3. heaven 2. Myopia! Ipziyshe oi B(apdagaz apa Tesppoiodu, KhBIRB-197: Admumapsei Epsguriop 5(apdaga Mom. 2001.

Aumayariye ai per://svgs.pivi dom/rybiisayopeLrv/ pEr://svgs. half house/rybiyasabyoperaelLirz197Lirvg-197. stew

Claims (1)

The formula of the invention , , , What and what , , The method of cryptographic transformation of information, which consists in the fact that the information sequence is presented in the form of 128-bit blocks, which are subject to iterative processing by primitive cryptographic transformations: substitution (zybziyshop) of bytes (ZyibVuievz) with a fixed table of substitutions of dimensions 8x256 - with the help of substitution blocks (5- blocks); functional operations of cyclic shifting of lines (ZpPiYKkOmMU5). - byte-by-byte shift of rows of the data array (Ziaye) by a distinct number of bytes, shuffling of columns (MixSoYptpv) - multiplication of data columns, considered as polynomials over SC(2 У), by a polynomial of the third degree d(x) by o) modulo X-1 and addition of a round key (AdaKotspaKeu), with the help of appropriate devices, which differs in that when performing the operation of adding a round key, a variable gamma of the function (0) is used, which is formed according to an iterative rule using a variable quad matrix M of the fourth order, chosen according to round key value. "- Official bulletin "Industrial Property". Book 1 "Inventions, useful models, topographies of integral SU microcircuits", 2007, M 5 04/25/2007. State Department of Intellectual Property of the Ministry of Education and Science of Ukraine. s s - s ;" name) name) name) - 50 sl s 60 b5