UA144143U - 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 iteratively processed by primitive cryptographic transformations: functional operations of cyclic shift and addition modulo 2 (ShiftRow) - using appropriate devices, substitution (substitution) - using substitution blocks (S-blocks); permutation - by means of blocks of mixing of cubes (P-blocks); 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 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 = ΜΜx -1 ++ over the primitive Galois binary field GF (2), using as a matrix Μ affine transformation variable inverse symmetric matrices, which are selected according to the value of the cyclic key, and that the functional mixing operation is not fixed but depends on the key that iterative processing by primitive cryptographic transformations occurs in the following sequence: functional operations of sliding coding (Slid Code), mixing (permutation), substitution (substitution), functional operations of cyclic shift and addition modulo 2 (ShiftRow).

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 (||, 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 multiple execution of the same groups of transformations, which provide the necessary conditions for the stability of the cryptographic transformation: scattering (with the help of 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 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 analogue is an 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 (reptshiayop) - with the help of cube shuffling blocks (Regtia blocks30); substitution (zyr5iyshiop) - using substitution blocks (5-blocks); functional operations of cyclic shift and addition modulo 2 (ZpPShKoOm) - using 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 5- the block forms a variable three-dimensional matrix of substitutions, and 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.x7" by VD over the primitive binary Galois field

SI(2), while variable inverse symmetric matrices are used as matrices M of the affine transformation, which are chosen according to the value of the cyclic key, and functional

The cyclic shift operations 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 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 mixing information data in three-dimensional space, that the functional shuffling operation is not fixed, but depends on the state of the key, and that the iterative processing by primitive cryptographic transformations takes place in the following sequence: functional operations of sliding coding (5IySode), shuffling (reptshaiiop), substitution (zirziysiop), functional operations of cyclic shift and addition by module 2 (ZPOIKOm/).

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 (ЗПийКкоММ/) - using of the corresponding devices, substitution (5!yB5iyshiop) - using blocks of substitutions (5-blocks); mixing (regttiiaiop) - with the help of cubes mixing blocks (P-blocks); functional operations of sliding coding (51st Sode) - 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 multiplicatively of the inverse element x' over the extended finite Galois field CE(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 choose according to the value of the cyclic key and that the functional shuffling operation is not fixed, but depends on the state of the key, and that iterative processing with primitive cryptographic transformations occurs in the following sequence: functional operations of sliding coding (ZiaSode), shuffling (reptshaiiop), substitution (z5z!yir5iyshiop ), functional operations of cyclic shift and addition modulo 2 (ZP ИНОмы).

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 mixing process.

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: functional operations of cyclic shift and addition modulo 2 (ZpPISHKOmM) - using appropriate devices, substitution (vyrviyshiop) - using blocks of substitutions (5-blocks); mixing (reptshayop) - with the help of cubes mixing blocks (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), while as a symmetric matrix M of the affine transformation, variable inverse symmetric matrices are used, which are chosen according to the value of the cyclic key, and that the functional shuffling operation is not fixed, but depends on the state of the key, and that the iterative processing by primitive cryptographic transformations takes place in the following sequence: sliding coding functional operations (51iiiaSoae), shuffling (reptshayop), substitution (zyB5iyshiop), functional operations of cyclic shift and addition modulo 2 (ZPiiKkOm/).

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

From 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 (depending 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 process of mixing information data in three-dimensional space.

Sources of information: 1. "RIR5 ROV 46-3" RGEOEVAI IMEOVMATIOM RAVOSEBBIMIa ZTAMOANVOV ROVI ISATIOM. RATA EMSAMRTIOM ZTAMOANVO (OE5) 1999 OKuoBbeg 25, Radez 26.

Nper/Lymlu. emeguzres.sot/MIZT/MIZT-RIRB/dompiovga.ryr?5res-RIRZ ROV 46-3.030171. rai 2. Patent of Ukraine for a utility model Me99696, IPC c09S 1/00 (2015.01). The method of cryptographic transformation of information / Biletskyi A.Ya., Navrotskyi D.O.; applicant and patent holder National Aviation University. - MO and 201404060; statement 04/16/2014; published 25.06.2015, Bul. Mo 12-5 b.

Claims (1)

USEFUL MODEL FORMULA A 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 (ZpPShKOm/) - with the help of appropriate devices, substitution (5yir5iyshiop) - using blocks of substitutions (5-blocks); shuffling (reppshayop) - with the help of cubes shuffling blocks (P-blocks); functional operations of sliding coding (5iiiSode) - 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 Z-block they form a variable three-dimensional matrix of substitutions, which is built by obtaining a 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 C(2), while as a matrix M affine transformation uses variable inverse symmetric matrices, which are chosen according to the value of the cyclic key, and that the functional shuffling operation is not fixed, but depends on the state of the key, and that iterative processing by primitive cryptographic transformations occurs in the following sequence: functional operations of sliding coding (51 and 14th Sode ), shuffling (regtshiiayop), substitution (5z!yr5iyshiop), functional operations of cyclic shift and addition modulo 2 (ZPIЙКкоММ/).