UA116471U - 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, which are subject to iterative processing by primitive cryptographic transformations: permutation - using mixing blocks of cubes (P-blocks); substitution - with the help of substitution blocks (S-blocks); functional operations of cyclic shift and addition on module 2 (ShiftRow) - by means of the corresponding devices, functional operations of sliding coding (SlidCode) - by means of the mixed Gray codes. The bit blocks of the information sequence are presented in the form of three-dimensional matrices (cubes), and that as an S-block form a variable three-dimensional matrix of substitutions, which is constructed by obtaining a multiplicative inverse element x-1 over the extended Galois finite field GF (28) and performing affine transformation y = Flies-1 ++ over the primitive Galois binary field GF (2), while the inverse matrix 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 sliding functional operations are not fixed but depend on the key state.

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 (reptiiayop) - using permutation blocks (P-blocks); substitution (zIyB5iyshiop ) - 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 the cryptographic transformation of information as a 5-block, a fixed matrix of substitutions is used, 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 parameter values are used landslide

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 (reptiiaiop) - using cubes shuffling blocks (blocks ReptiiZO); substitution (zyBv5iyshiop) - using blocks of substitutions (5-blocks); functional operations of cyclic shift and addition according to module 2 (ZPSHANOM) - 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 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 CE(25) and by performing the affine transformation y-M .x"B over the primitive binary Galois field CE(2), and 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 closest analogue are that for the cryptographic transformation of information as a 5-block, a fixed substitution matrix acts, 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, and 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 dynamically changing substitution matrices as a 5-block, 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 parameters of sliding coding dynamically change in 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: shuffling (reptiiyaop) - with the help of blocks of shuffling cubes (P-blocks) ; substitution (5!irviyshiop) - using substitution blocks (5-blocks); functional operations of cyclic shift and addition modulo 2 (ZNSHNOmM) - with the help of appropriate devices, functional operations of sliding coding (5iiYaiSode) - with the help of mixed Gray codes, in which, according to a useful model, the bit blocks of the information sequence are presented in the form of three-dimensional matrices (cubes ), and that the qualities of the 5-block form a variable three-dimensional substitution matrix, which is constructed by obtaining the multiplicative inverse element x' over the extended finite Galois field CIE(28) and by performing the affine transformation y-M.x-148 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 operations of sliding coding 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 sliding coding process.

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: shuffling (regtshiiyayop) - with the help of cubes shuffling blocks (P-blocks); substitution (5!Ir5iyshiop) - using blocks of substitutions (5-blocks); functional operations of cyclic shift and addition according to module 2 (ZPSHAAOmM) - 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 SB(23) and by performing the affine transformation (1) over the primitive binary Galois field CE(2), while as a symmetric matrix M affine transformation uses variable inverse symmetric matrices that are chosen according to the value of the cyclic key, and that the functional operations of sliding coding 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 selected 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 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 (remaining 7 of 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 is possible to apply dynamically changing matrices of substitutions as a 5-block at each iteration of the cryptographic transformation of information and

From different sizes of sliding coding, which allows you to flexibly change the parameters of cryptographic processing and dynamically control the process of sliding coding of information data in three-dimensional space.

Sources of information: 1. "RIR5 ROV 46-3" GEOEVAI IMEOVMATIOM RAVOSEBBIMIa ZTAMOANVOV ROVI ISATIOM. RATA EMSAMRTIOM ZTAMOANVO (OE5) 1999 OKiobeg 25, radez 26. pEruLlymly. emeguzres.sot/MIZT/MIZT-RIRB/dompioai. ryr"zres-RIRZ ROV 46-3.030171. rai. 2. Method of cryptographic transformation of information: patent 94189: IPC 2014-01 /

Biletskyi A.Ya., Navrotskyi D.O.; patent holder National Aviation University. - MO 201312117; statement 16.10.2013; published 10.11.2014, Bull. Mo 21.-5 p.m.

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: shuffling (reptiiyaop) - with the help of cubes shuffling blocks (P-blocks); substitution (zibviyshiop) - using substitution blocks (5-blocks); functional operations of cyclic shift and addition modulo 2 (ZPSHNVOmU) - with the help of appropriate devices, functional operations of sliding coding (5iiySode) - 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), and that as a 5-block they 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(29) 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 operations of the sliding are not fixed, but depend on the state of the key.