UA130671U - METHOD OF CRYPTOGRAPHICAL TRANSFER OF INFORMATION - Google Patents

Abstract

The method of cryptographic transformation of information is that the information sequence is submitted in the form of bit blocks, which are subject to iterative processing by primitive cryptographic transformations: functional cyclic shift operations and addition modulo 2 (ShiftRow) - using the appropriate devices; substitution using substitution blocks (S-blocks); sliding coding functional operations (SlidCode) - using mixed Gray codes, the bit blocks of the information sequence are presented in the form of three-dimensional matrices (cubes) and as an S-block form a variable three-dimensional matrix of substitutions, which is constructed by obtaining a multiplicatively inverse width x-1 element the Galois field GF (28) and by performing the affine transformation y = M (x-1 + (over the primitive binary Galois field GF (2), using the variables M of affine transformation using the variables inverted symmetric matrices They are based on the value of the cycle key, and that the functional substitution operations are not fixed, but depend on the state of the key.

Description

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

A known method of cryptographic transformation (1|), 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 (regtshaiiyop) using permutation blocks (P-blocks); substitution (5!yB5iyshiop ) using substitution blocks (5-blocks); functional operations of cyclic shift and addition modulo 2 using appropriate devices. Iterative processing consists in repeatedly performing the same groups of transformations that provide the necessary conditions for the stability of cryptographic transformation: scattering (using P-blocks ) and mixing (with the help of 5-blocks) information data.

The disadvantages of this method are that for the cryptographic transformation of information as a 5-block, a fixed matrix of substitutions acts, which does not allow to flexibly change the parameters of cryptographic processing and dynamically control the process of shuffling information data, as well as the fact that for the functional shuffling operation, fixed values of the shift parameters are used .

The closest to the proposed technical solution, chosen as the closest analogue, is the improved method of cryptographic transformation (21), which is based on the fact that the information sequence is presented in the form of bit blocks, which are subject to iterative processing by primitive cryptographic transformations: shuffling (regtshaiyyop) using blocks shuffling of cubes (Regtii30O blocks); substitution (5!yr5iishiop) using substitution blocks (5-blocks); "sliding coding" (5iiideSode) - with the help of appropriate devices, which differs in that the bit blocks of the information sequence are presented in the form of three-dimensional matrices (cubes) and as a 5-block form a variable three-dimensional matrix of substitutions, which is constructed by obtaining the multiplicative inverse element x" over the extended finite Galois field SI(28) and by performing the affine transformation y-M.x-148 over the primitive binary Galois field CE( 2), at the same time, as the matrix M of the affine transformation, variables vol erne symmetric matrices which are chosen according to

From the value of the cyclic key, and using "sliding coding".

The disadvantages of the closest analogue are that for cryptographic transformation of information, a fixed substitution matrix acts as a 5-block, which does not allow to flexibly change the parameters of cryptographic processing and dynamically control the process of substitution of information data, and that for cryptographic transformation of information, the substitution parameters are fixed.

The basis of a useful model is the task of creating a method of cryptographic transformation of information, which, due to the use of a 5-block dynamically changing matrix of substitutions, will make it possible to flexibly change the parameters of cryptographic processing and dynamically control the process of substitution of information data in three-dimensional space, and the fact that the substitution parameters change dynamically depending on the state of the key.

The task is solved due to the fact that the method of cryptographic transformation of information, which consists in the fact that the information sequence is presented in the form of bit blocks, which are subject to iterative processing by primitive cryptographic transformations; functional operations of cyclic shift and addition according to module 2 (ZpPiykKOmM) using the appropriate devices; substitution (zyB5iyshiop) using substitution blocks (5-blocks); functional operations of sliding coding (5IiySode) using mixed Gray codes, in which the bit blocks of the information sequence are presented in the form of three-dimensional matrices (cubes), and as a 5-block form a variable three-dimensional substitution matrix, which is constructed by obtaining the multiplicative inverse element x" over the extended final by the Galois field CE(28) and by performing the affine transformation y-M.x'-B8 over the primitive binary Galois field

CE(2), while variable inverse symmetric matrices are used as the matrix M of the affine transformation, which are chosen according to the value of the cyclic key, and that the functional substitution operations are not fixed, but depend on the state of the key.

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 and dynamically control the process of substituting information data.

The method of cryptographic transformation of information is realized by the fact that the information sequence is presented in the form of 256 bit blocks, which are subject to iterative processing by primitive cryptographic transformations: functional operations of cyclic shift and 60 addition modulo 2 (ZpPiIYKOmM) - with the help of appropriate devices; substitution

(vyrviyshiop) - using substitution blocks (5-blocks); functional operations of sliding coding (5iIia4Soade) - with the help of mixed Gray codes. As a 5-block, there is a variable matrix of substitutions, which is constructed by obtaining the multiplicative inverse element x' over the extended finite Galois field CE(28) and by performing the affine transformation (1) over the primitive binary Galois field CE(2), while as a symmetric matrix M the affine transformation uses variable inverse symmetric matrices that are chosen according to the value of the cyclic key, and that the functional substitution operations are not fixed but depend on the state of the key.

The cyclic key is generated from the encryption key using the key generation algorithm. The length of the cyclic key is equal to the length of the block. Cycle keys are generated from the encryption key using key expansion. The extended key is a linear array of 4-byte words. That is, at each iteration of the cryptographic transformation, a corresponding symmetric matrix M is used, which can be chosen from a large set of inverse matrices with the help of a cyclic 4-byte key. This makes it possible to flexibly change the shuffling matrix in the process of cryptographic transformation and, accordingly, to dynamically control the process of substituting information data.

Depending on the stage of the round key, the sliding coding parameter is selected by adding modulo 2 all bytes of the key, setting 1 in the lower digit of the result of addition (to form an odd value) and getting rid of the higher digit of the result of addition (remaining 7 of the 8 significant bits). The final value determines the amount of shift in the current round.

Thus, due to the use of variable inverse symmetric matrices and a variable (dependent on the round key) shift function, it will be possible to apply dynamically changing substitution matrices and different shift values as a 5-block at each iteration of the cryptographic transformation of information, which makes it possible to flexibly change the parameters of cryptographic processing and dynamically control the process of substituting information data in three-dimensional space.

Sources of information: 1. "RIP5 ROV 46-3" GEOEVAI IMEOVMATIOM RAVOSEBBIMI ZTAMOANVOZ ROVI ISATIOM. RATA EMSAMRTIOM ZTAMOANVO (OE5) 1999 OKuoBbeg 25, Radez 26.

Co., Ltd.) Ner/Lymlu. emeguzres.sot/MIZT/MIZT-RIRB/dompioaa.ryr?5res-BIR5 RIV 46-3.030171. heaven 2. Patent of Ukraine for a utility model Mo 99696, IPC (009С 1/00 (2015.01) Method of cryptographic transformation of information/ Biletskyi A.Ya., Navrotskyi D.O.; applicant and patent holder National Aviation University. - Mo 201404060; application, 16.04 .2014: published 25.06.2014, Bul. Mo 12-5 p.

Claims (1)

USEFUL MODEL FORMULA The method of cryptographic transformation of information, which consists in the fact that the information sequence is presented in the form of bit blocks, which are subject to iterative processing by primitive cryptographic transformations: functional operations of cyclic shift and addition modulo 2 (ZNSHNOmM) - with the help of appropriate devices; substitution (zIyB5iyshiop) using blocks of substitutions (5-blocks); functional operations of sliding coding (51iaSoaeee) - with the help of mixed Gray codes, which differs in that the bit blocks of the information sequence are presented in the form of three-dimensional matrices (cubes) and as a 5-block form a variable three-dimensional matrix of substitutions, which is built by obtaining the multiplicative inverse element x! " over the extended finite Galois field CE(25) and by performing the affine transformation y-M.x"-8 over the primitive binary Galois field CE(2), while variable inverse symmetric matrices are used as the matrix M of the affine transformation, which are chosen according to the value of the cyclic key, and that the functional substitution operations are not fixed, but depend on the state of the key. 00 Computer keyboardG. Payalnikovo (00000000 Ministry of Economic Development and Trade of Ukraine, str. M. Hrushevsky, 12/2, m. Kyiv, 01008, Ukraine SE "Ukrainian Institute of Industrial Property", str. Glazunova, 1, m. Kyiv - 42, 01601