UA130050U - METHOD OF CRYPTOGRAPHICAL TRANSFER OF INFORMATION - Google Patents

Abstract

A method of cryptographic transformation of information, which is that the information sequence is submitted 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) and as an S-block form a variable three-dimensional matrix of substitutions, which is constructed by obtaining a multiplicatively inverse x-1 element over the extended Galois finite field GF (28) and by performing the affine transformation y = Μ ( x-1 + β over the primitive Galois binary field GF (2), using the matrix Μ of the affine transform using variable inverted symmetric matrices, which are selected according to the value of the cycle key, and functional mixing and loop operations the personal shift is not fixed, but depends 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 (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 to the proposed technical solution, chosen as the closest analogue, 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 (repetition) - using blocks for mixing cubes (ReptiiZO blocks); substitution (zIyB5iyshiop) - using blocks of substitutions (5-blocks); functional operations of cyclic shift and addition modulo 2 (ZНЩНОммм) - 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, and it 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 .x7-8 over the primitive Galois binary field SKE(2), while inversely symmetric variables are used as the matrix M of the affine transformation is that for

From the cryptographic transformation of information as a 5-block, a fixed substitution matrix stands out, 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 cryptographic transformation of information cyclic shift parameters are fixed.

The useful model is based on the task of creating a method of cryptographic transformation of information, which, due to the use of four three-dimensional cryptographic transformations (shuffling, substitution, cyclic shift and sliding coding), will make it possible to flexibly change the parameters of cryptographic processing and dynamically control the process of substituting information data in three-dimensional space , and that the functional operations of shuffling and cyclic shift are not fixed, but depend 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 as a 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 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 the functional operations of shuffling and cyclic shift 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 of information data and dynamically control the process of shuffling and cyclic shifting.

The method of cryptographic transformation of information is realized by the fact that the information sequence 60 is presented in the form of 256 bit blocks, which are subject to iterative processing by primitive cryptographic transformations: shuffling (regtshiiaiiop) - 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 CE(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, and the functional operations of shuffling, substitution, cyclic shift, and 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 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 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) 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 mixing process and

From the cyclic shift 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/dompiosaya. ryr"zres-BIRO ROV 46-3.030171. rai. 2. Patent of Ukraine for utility model Mo 99696, IPC Сс09С 1/00 (2015.01). Method of cryptographic transformation of information / Biletskyi A.Ya., Navrotskyi D.O.; applicant and patent owner National Aviation University - ME 0201404060; application 04/16/2014; published 06/25/2015, 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: shuffling (reptiiyaop) - with the help of cubes shuffling blocks (P-blocks); substitution (zibv5iyshiop) - 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 (5iIiySode) - 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 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-x7"--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 the functional operations of shuffling and cyclic shift are not fixed, but depend on the state of the key.