UA140090U - 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: functional operations of cyclic shift and addition modulo 2 (ShiftRow) - using appropriate devices, 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. Bit blocks of the information sequence are presented in the form of three-dimensional matrices (cubes). As an S-block, a variable three-dimensional substitution matrix is formed, which is constructed by obtaining a multiplicative inverse element x-1 over the extended Galois finite field GF (28) and by performing an affine transformation y = Flies-1 ++ over a primitive Galois binary field GF (2). Variable inverse symmetric matrices are used as the Μ affine transformation matrices, which are selected according to the value of the cycle key, the functional operations of mixing and sliding coding are not fixed, but depend on the state of the key. Iterative processing by primitive cryptographic transformations occurs in the following sequence: functional operations of cyclic shift and addition modulo 2 (ShiftRow), mixing (permutation), substitution (substitution), functional operations of sliding coding (SlidCad).

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.

There is 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 (repetition) using permutation blocks (P-blocks); substitution (zIyB5iyshiop) - using blocks of substitutions (5-blocks); functional operations of cyclic shift and addition by modulo 2 - with the help of appropriate devices. Iterative processing consists in multiple execution of the same groups of transformations that provide the necessary conditions for stability of cryptographic transformation: scattering (using P-blocks) and mixing (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 to quickly change the parameters of cryptographic processing and dynamically control the process of shuffling of information data, as well as the fact that fixed values of parameters are used for the functional shuffling operation landslide

The closest analogue to the proposed useful model is the 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 (reptiiaiop) using cube shuffling blocks (Reptia blocks 30 ); substitution (5!IB5iyshiop) - with the help of substitution blocks (5-blocks); functional cyclic shift and addition operations modulo 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 as a 5-block form a variable three-dimensional matrix of substitutions, and 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 the matrices M of the affine transformation use variable inverses imetric 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 method are that for cryptographic transformation of information a fixed matrix of substitution acts as a 5-block, 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 the fact that the cyclic shift parameters are fixed for the cryptographic transformation of information.

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 shuffling and sliding coding of information data in three-dimensional space, and that the functional operations of shuffling and sliding coding are not fixed, but depend on the state of the key, and that iterative processing by primitive cryptographic transformations takes place in the following sequence: functional operations of cyclic shift and addition modulo 2 (ZPySHAoOm), shuffling (reptshaiyop), substitution (zirviyshiop), functional operations of sliding coding (51iaSode).

The problem is solved by 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 (ZPIINOmM) - with the help of appropriate devices , substitution (5!йр5ийшиоп) - using blocks of substitutions (5-blocks); mixing (reptiiaiop) - with the help of cubes mixing blocks (P-blocks); functional operations of sliding coding (5iIiYa4Sode) - 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 as a 5-block form a variable three-dimensional substitution matrix, which is constructed by obtaining of the multiplicatively inverse element x' over the extended finite Galois field CE(28) and by performing the affine transformation y-Mx-148 over the primitive binary Galois field (E(2), while as matrices M of the affine transformation using variable inverse symmetric matrices that choose according to the value of the cyclic key and that the functional operations of shuffling 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: ), substitution (5!yB5iyshiop), functional operations sliding coding (51iaSoavier).

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 sliding coding.

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 (5PISHNOMm) - using appropriate devices, substitution (vibyviyshiop) - using blocks of substitutions (5-blocks); shuffling (reptshiayop) - with the help of cubes shuffling blocks (P-blocks); functional operations of sliding coding (BidSode) - with the help of 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 that are chosen according to the value of the cyclic key and that the functional operations of shuffling 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 by module 2 (Z5pPShNOm), shuffling (reptshaiyop), substitution (5!yrziyshiop), functional operations of sliding coding (51IiaSoavye).

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, with the help of a cyclic 4-byte key, can

Z is chosen from a large set of inverse matrices. 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 all the bytes of the key modulo 2, setting the result of addition to the lower digit (to form an odd value) and getting rid of the higher digit of the result of addition (remaining 7 of 8 significant runs). 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 use as a 5-block dynamically changing substitution matrices and various values of sliding coding 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 and sliding coding of 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 OKiobeg 25, radez 26. pEruLlymly. emeguizres.sot/MIZT/MIZT-RIRB/dompiosad. rpyr?b5res-BIR5 ROV 46-3.030171. rai 2. Patent of Ukraine for utility model Me99696, IPC p:09С 11/00 (2015.01). The method of cryptographic transformation of information / Biletskyi A.Ya., Navrotskyi D.O.; applicant and patent holder National Aviation University. - MOI 201404060; statement 16.04.2014; published 25.06.2015, Bul. Me 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 modulo 2 (ZPSHNOmM) - using appropriate devices, substitution (5!Irviyshiop ) - using substitution blocks (5-blocks); mixing (reptiiyayop) - with the help of blocks 60 mixing cubes (P-blocks); functional operations of sliding coding (5iiaSode) - 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 built by obtaining the multiplicative inverse element x" over the extended finite Galois field CE(25) and by performing the affine transformation y-M.x"--rD over the primitive binary Galois field CE(2), while as matrices M of the affine transformation variable inverse symmetric matrices are used, which are chosen according to the values of the cyclic key, the functional operations of scrambling and sliding coding are not fixed, but depend on the state of the key; iterative processing with primitive cryptographic transformations takes place in the following sequence: functional operations of cyclic shift and addition modulo 2 (5PyVoOm), shuffling (reptiiaiiyop), substitution (virviyshiop), functional operations of sliding coding (5iIiiaSoavd).