UA133744U - METHOD OF CRYPTOGRAPHICAL TRANSFER OF INFORMATION - Google Patents

Abstract

A method of cryptographic transformation of information, in which the information sequence is presented in the form of bit blocks that are subject to iterative processing by primitive cryptographic transformations: permutation - using blocks of mixing cubes (P-blocks); substitution - by means of substitution blocks (S-blocks); functional cyclic shift and modulation operations 2 (ShiftRow) - using appropriate devices, functional sliding coding operations (SlidCode) - using mixed Gray codes. The bit blocks of the information sequence are presented in the form of three-dimensional matrices (cubes). As an S-block, a variable three-dimensional permutation matrix is formed, which is constructed by obtaining a multiplicatively inverse x-1 element over the extended Galois finite field GF (28) and by performing an affine transformation y = M (x-1 + (over the primitive binary Galois GF field (2 ) As the affine transformation matrix M, we use variable inverted symmetric matrices, which are selected according to the value of the cycle key. Functional operations of substitution, mixing and cyclic shifting and addition modulo 2 are not fixed but depend on the state of the key. processing primitive cryptographic transformations carried out in the following order: substitution (substitution), stirring (permutation), functional cyclic shift operations and addition modulo 2 (ShiftRow), functional coding moving operations (SlidCode).

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 (reptshayop) - using blocks of permutations (P-blocks); substitution (5ЙиБ5ийшиоп ) - with the help of substitution blocks (5-blocks); functional operations of cyclic shift and addition modulo 2 - with the help of appropriate devices. Iterative processing consists in repeatedly performing the same groups of transformations that provide the necessary conditions for the stability of the cryptographic transformation: scattering (using P -blocks) and shuffling (using 5-blocks) of information data.

The disadvantages of this method are that for cryptographic transformation of information in quality

A fixed matrix of substitutions stands out from the block, 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 fixed values of shift parameters are used for the functional shuffling operation.

The closest analogue to the proposed useful model is the improved method of cryptographic transformation |2), 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 |(regtiiatsiop) - with the help of cube shuffling blocks ( blocks of Regtia3O); substitution (zyB5iyshiop) - using substitution blocks (5-blocks); functional operations of cyclic shift and addition according to module 2 (ZPSHAOm) - with the help of appropriate devices. At the same time, the bit blocks of the information sequence are presented in the form of three-dimensional matrices (cubes) and which 5-blocks form a variable three-dimensional matrix of substitutions, which is constructed by obtaining the multiplicative inverse element x" over the extended finite Galois field CE(25) and by performing the affine transformation y - M . x" and D over the primitive Galois binary field CE(2). Variable inverse symmetric matrices, which are chosen, are used as the matrix M of the affine transformation

According to the value of the cyclic key, the functional operations of the cyclic shift are not fixed, but depend on the state of the key.

The disadvantages of the closest analogue are that a fixed substitution matrix acts as a 5-block for cryptographic transformation of information, which does not allow to flexibly change the parameters of cryptographic processing and dynamically control the process of substitution of information data, in addition, the substitution parameters and cyclic shift 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 four three-dimensional cryptographic transformations (substitution, shuffling, cyclic shift and sliding coding), which will make it possible to flexibly change the parameters of cryptographic processing and dynamically control the processes of substitution, shuffling and cyclic shift and adding modulo 2 information data in three-dimensional space.

The task is solved by the method of cryptographic transformation of information, in which the information sequence is presented in the form of bit blocks, which are subject to iterative processing by primitive cryptographic transformations: shuffling (regtshishayop) - using cube shuffling blocks (P-blocks); substitution (5yiB5iishiop) - using blocks of substitutions (5-blocks); functional operations of cyclic shift and addition according to modulo 2 (ZPSHAOm) - with the help of appropriate devices, functional operations of sliding coding (BidSode) - with the help of mixed Gray codes, according to a useful model, bit blocks of the information sequence are presented in the form of three-dimensional matrices (cubes), as a Z-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 SKE(28) 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, the functional operations of substitution, shuffling and cyclic shift and addition modulo 2 are not fixed, but depend on the state of the key, and iterative processing with primitive cryptographic transformations is carried out in the following sequence: substitution (ziBziyshiop), shuffling (reppshaikop), functional operations of cyclic shift and addition by modulo 2 (ZPIYKkOm/), because functional operations of sliding coding (51iiSode).

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 and dynamically control the processes of substitution, shuffling and cyclic shift and addition according to module 2.

The method of cryptographic transformation of information is implemented 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: shuffling (reptshayop) - with the help of cubes shuffling blocks (P-blocks); substitution (zIirbiysiop) - with the help of substitution blocks (5-blocks); functional operations of cyclic shift and addition according to module 2 (ZPSHAOm) - with the help of appropriate devices; functional operations of sliding coding (BidSoade) - using 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 SBB(23) and by performing the affine transformation (1) over the primitive binary Galois field CE(2), at the same time as a symmetric matrix M affine transformation uses variable inverse symmetric matrices, which are chosen according to the value of the cyclic key, the functional operations of substitution, shuffling and cyclic shift and addition modulo 2 are not fixed, but depend on the state of the key, and that iterative processing by primitive cryptographic transformations is carried out in the following sequence: substitution (zir5iyshiop), shuffling (regtshaiop), functional operations of cyclic shift and addition modulo 2 (ZPIYKOmM), functional operations of sliding coding (5IiySode).

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 dynamically control the process of shuffling, substitution, cyclic shift and sliding coding of information data.

Depending on the state of the round key, the parameter of shuffling, substitution, cyclic shift and sliding coding 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 (remains 7 with 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) substitution function, it is possible to apply dynamically changing substitution matrices and different values of sliding coding 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 processes of substitution, mixing and cyclic shift and addition according to module 2 of information data in three-dimensional space.

Sources of information: 1. TIRB ROV 46-3" EEROEVAI IMEOVMATIOM RVOSEB5IMA ZTAMOANVNOB ROVI SATIOM. rATA EMSAMRTIOM ZTAMOANVO (OE5) 1999 OkyuBbeg 25, radez 26. perULlimly. emeguizres.sot/MIZT/MIZT-RIRI/dompioaia. rRByrROV7zres 4RByr57zres -3.0301 71. rai 2. Patent of Ukraine for a utility model Me99696, IPC (с09С 11/00 (2015.01). Method of cryptographic transformation of information / Biletskyi A.Ya., Navrotskyi D.O.; applicant and patent owner National Aviation University. - Mo и201404060; application 04/16/2014; published 06/25/2015, Bul. Mo 12-5 p.

Claims (1)

USEFUL MODEL FORMULA A method of cryptographic transformation of information, in which the information sequence is presented in the form of bit blocks, which are subject to iterative processing by primitive cryptographic transformations: shuffling (regtshaiyop) - using cube shuffling blocks (P- blocks); substitution (zirziyshiop) - with the help of substitution blocks (5-blocks); functional operations of cyclic shift and addition according to module 2 (ZpPShKOm) - with the help of appropriate devices, functional operations of sliding coding (51iiiaSode) - with the help of mixed Gray codes, which is distinguished by the fact that the bit blocks of the information sequence are presented in the form of three-dimensional matrices (cubes), as a 5-block form a variable three-dimensional matrix of substitutions that 60 is constructed by obtaining the multiplicative inverse element x" over the extended finite Galois field CE(28) and by performing the affine transformation y-M.x"-8 over the primitive binary Galois field CE (2), while the variables M are used as the matrix M of the affine transformation inverse symmetric matrices, which are chosen according to the value of the cyclic key, functional operations of substitution, shuffling and cyclic shift and addition modulo 2 are not fixed but depend on the state of the key, and iterative processing with primitive cryptographic transformations is carried out in the following sequence: substitution (ziirziyshiop), shuffling (reptshiiatiop), functional operations of cyclic shift and addition by module 2 (ZpPiiKoOmy), functional operations of sliding coding (5iiasSoae).