UA140080U - METHOD OF CRYPTOGRAPHIC TRANSFORMATION OF INFORMATION - Google Patents

Abstract

The method of cryptographic transformation of information is that the information sequence is presented in the form of bit blocks to be iteratively processed by primitive cryptographic transformations: functional operations of cyclic shift and addition modulo 2 (ShiftRow) using appropriate devices, substitution using substitution blocks (S-blocks); mixing (permutation) using blocks for mixing cubes (P-blocks); SlidCode functional operations using mixed Gray codes.

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|Й), 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! yB5iysiop) using substitution blocks (5-blocks); functional operations of cyclic shift and addition modulo 2 using appropriate devices. Iterative processing consists in multiple execution of the same groups of transformations, which provide the necessary conditions for the stability of cryptographic transformation: scattering (using P- blocks) and shuffling (using 5-blocks) of information data.

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

The closest to the proposed technical solution is an 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 (reptshayop) using blocks of shuffling cubes (blocks of Reptia3O ); substitution (5!yiB5iyshiop) using blocks of substitutions (5-blocks); functional operations of cyclic shift and addition modulo 2 (ZpShyKOoMm) using the appropriate devices. At the same time, the bit blocks of the information sequence are presented in the form of three-dimensional matrices (cubes) and as a Z-block they form a variable three-dimensional matrix of substitutions, and it 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"--8 over the primitive Galois binary field CE(2), while as a matrix

M affine transformation uses variable inverse symmetric matrices, which are chosen

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

The disadvantages of the method are that for the 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 information data substitution, and that for the cryptographic transformation of information, the substitution parameters are fixed, and that , that for the cryptographic transformation of information, the 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), will make it possible to flexibly change the parameters of cryptographic processing and dynamically control the process of cyclic shift and addition according to module 2, substitution and sliding coding of information data in three-dimensional space, and that functional operations of cyclic shift and addition modulo 2, substitution and sliding coding are not fixed, but depend on the stage of the key, and that iterative processing by primitive cryptographic transformations occurs in the following sequence: functional operations of cyclic shift and addition by modulo 2 (ZPIIKkOMm/), shuffling (reptshiaiyop), substitution (zyBv5iyshiop), functional operations of sliding coding (51IiySode).

The problem 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 modulo 2 (ZPYKOmM) - using corresponding devices, substitution (zyB5iyshiop) using blocks of substitutions (5-blocks); mixing (regtshayop) with the help of cube mixing blocks (P-blocks); functional operations of sliding coding (5IiiiSode) using mixed Gray codes, in which media and invention, 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, it is constructed by obtaining a multiplicative inverse element x" over the extended finite Galois field CE(29) and by performing the affine transformation y-M'x"-p over the primitive binary Galois field CE(2), while variable inverse symmetric matrices are used as the matrix M of the affine transformation, which choose according to the value of the cyclic key and that the functional operations of cyclic shift and addition modulo 2, substitution and sliding coding are not fixed, but depend on the state of the key, and that iterative processing by primitive cryptographic transformations occurs in the following sequence: functional operations of cyclic shift and addition modulo 2 (ZPyYKom/), shuffling (regtshayop), substitution (select5ШШshio n), functional operations of sliding coding (5iIiaSoae).

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 process of cyclic shift and addition according to module 2, substitution and sliding coding.

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 addition modulo 2 (ZpPShKOmM) - with the help of appropriate devices, substitution (5ireiyshiop) with the help of blocks substitution (5-blocks); change) your (regtshayop) with blocks of shuffling cubes (P-blocks); 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 CE(25) and by performing the affine transformation (1) over the primitive binary Galois field CE(2), at the same time as a symmetric matrix M of the affine transformation use variable inverse symmetric matrices that are chosen according to the value of the cyclic key, and that the functional operations of cyclic shift and addition modulo 2, substitution, and sliding coding are not fixed, but depend on the stage of the key, and that the iterative processing by primitive cryptographic transformations takes place in of the following sequence: functional operations of cyclic shift) and addition by modulo 2 (ZpiiKoOm/), shuffling (regptshaiop), substitution (ziB5iishiop), functional operations of sliding coding (51iaSoae).

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 stage 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 (depending on the round key) substitution function, it will be 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 process of cyclic shift and addition according to module 2, substitution and sliding coding of information data in three-dimensional space.

Sources of information: 1. "RGIRB5 ROV 46-3" EESEVAI IMEOVMATIOM RAEOSEBBIMY 5BIAMOAKOV ROVI SATIOM. RATA EMSAMRTIOM ZTAMOANVO (OE5) 1999 OKuoBbeg 25, radez 26. pEruLlymly. emeguzres.sot/MIZT/MIZT-RIRB/dompioai. ryr"zres- BIR ROV 46-3.030171. rai 2. Patent of Ukraine for utility model Me99696, IPC (09С 11/00 (2015.01). Method of cryptographic transformation of information / Bilenky A.Ya., Navrotskyi D.O.; applicant and patent owner National Aviation University - MO 201404060; application 04/16/2014; published 06/25/2015, Bulletin 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 by bo modulo 2 (ZPISHKOMm) using appropriate devices, substitution ( with the help of substitution blocks (5-blocks); shuffling (regtshiayop) using cube shuffling blocks (P-blocks); functional operations of sliding coding (5iiiSode) using mixed Gray codes, which is distinguished by the fact that the bit blocks of the information sequence are presented in the form of a three-dimensional matrix (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 by 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 cyclic key, and that the functional operations of cyclic shift and addition modulo 2, substitution and sliding coding are not fixed, but depend on the stage of the key, and that iterative processing by primitive cryptographic transformations occurs in the following sequence: functional operations of cyclic shift and addition modulo 2 ( ZpPiYKOm), mixing (reptshaiyop), substitution (5!yr5iyshiop), fu nctional operations of sliding coding (5iiasSoae).