UA143956U - 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. The bit blocks of the information sequence are presented in the form of three-dimensional matrices (cubes), as the S-block forms a variable three-dimensional matrix of substitutions, which is constructed by obtaining a multiplicative inverse element b-1 over the extended Galois finite field GF MMM-1 ++ over the primitive Galois binary field GF (2). As the matrix M of the affine transformation, variable inverse symmetric matrices are used, which are selected according to the value of the cyclic key. The functional operation of the substitution is not fixed, but depends on the state of the key. The iterative processing of primitive cryptographic transformations occurs in the following sequence: functional operations of sliding coding (SlidCode), mixing (permutation), substitution (substitution), functional operations of cyclic shift and addition modulo 2 (ShiftRow).

Description

The utility 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 (reptiiayop) - using permutation blocks (P - blocks); substitution (zIyB5iyshiop) - using blocks of substitutions (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 that provide the necessary conditions for the stability of the cryptographic transformation: scattering (using P - blocks) and mixing (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 (reptiiyaop) - using cube shuffling blocks ( blocks of ReptiyaZO); substitution (zyB5iyshiop) - with the help of substitution blocks (5 - blocks); functional operations of cyclic shift and addition modulo 2 (5

Vomi) - 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 built by obtaining the multiplicative inverse element XX! over the extended finite Galois field CE(28) and by performing the affine transformation y-M.y- 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

From 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 - the closest analogue 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 substitution of information data, and that for the cryptographic transformation of information the substitution parameters are fixed , and that for the cryptographic transformation of information, the 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 (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 substitution of information data in three-dimensional space, and that the functional substitution operation is not fixed, but depends on the state of the key, and that the iterative processing with primitive cryptographic transformations occurs in the following sequence: functional operations of sliding coding (5iIiySode), shuffling (reptshayop), substitution (5!yBr5iyshiop), functional operations of cyclic shift and addition by module 2 (ZP Vomu).

The problem is solved due to the fact that in 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 modulo 2 (ZP Com) - by using appropriate devices, substitution (5!rviyshiop) - using substitution blocks (5 - blocks); mixing (reptiiaiop) - with the help of blocks mixing cubes (P - blocks); functional operations of sliding coding (54 Sode) - with the help of mixed Gray codes, according to a useful model, bit blocks of the information sequence are presented in the form of three-dimensional matrices (cubes), as a 5-block form a variable three-dimensional substitution matrix, which is built by obtaining a multiplicative inverse element in over the extended finite Galois field CE(28) and by performing the affine transformation y-M.y- 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 bo value cyclic key, while the functional operation of substitution is not fixed, but depends on the state of the key, and iterative processing with primitive cryptographic transformations occurs in the following sequence: functional operations of sliding coding (54 Sode), shuffling (reptshayop), substitution (5!IBrziyshiop), functional operations operations of cyclic shift and addition according to modulo 2 (ZPiY Noomi).

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 substitution 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 according to modulo 2 (ZP Nom) - with the help of appropriate devices, substitution (vyrviyshiop) - according to using substitution blocks (5 - blocks); mixing (reptiiaiop) - with the help of blocks mixing cubes (P - blocks); functional operations of sliding coding (51st Sode) - 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 u over the extended finite Galois field CE(28) and by performing the affine transformation (1) over the primitive binary Galois field CE(2), while as a symmetric matrix M of the affine transformations use variable inverse symmetric matrices, which are chosen according to the value of the cyclic key, the functional substitution operation is not fixed, but depends on the state of the key, and iterative processing by primitive cryptographic transformations occurs in the following sequence: functional operations of sliding coding (51-4 Sode), shuffling (reptiiaiop ), substitution (zyb5iyshiop), functional operations of cyclic shift and addition modulo 2 (Pii Mohm).

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 enables the cryptographic process

From the transformation, it is possible to flexibly change the shuffling matrix 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 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 (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 process of substituting 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. - R. 26. pEruLlymly.emeguzres.sot/MIZT/MIZT-RIRB/dompioai. ryr?zres-RIR5 ROIV 46-3.030171. rai 2. Patent of Ukraine for a utility model Mo 99696, IPC Сс09С 1/00 (2015.01). The method of cryptographic transformation of information / Biletskyi A.Ya., Navrotskyi D.O.; applicant and patent holder National Aviation University. - Me and 201404060; statement 16.04.2014; published 25.06.2015, Bull. 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 (ZPSHNOmM) - with the help of appropriate devices, substitution ( 5!irviyshiop) - using blocks of substitutions (5-blocks); shuffling (reptiiyayop) - with the help of cubes shuffling blocks (P-blocks); functional operations of sliding coding (5iiaSode) - with the help of mixed Gray codes, which are distinguished by the fact that the bit blocks of the information sequence are presented in the form of three-dimensional matrices (cubes), as a 5-block form a variable three-dimensional matrix of substitutions, which is built by obtaining a multiplicative inverse element in " over the extended finite Galois field CE(23) and by performing the affine transformation y-M.-y7--D 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 accordingly to the value of the cyclic key, the functional substitution operation is not fixed, but depends on the state of the key, while iterative processing by primitive cryptographic transformations occurs in the following sequence: functional operations of sliding coding (ZidSode), shuffling (reptiiaiop), substitution (5!IB5iysiop), functional operations of cyclic shift and addition by modulo 2 (CONNECTIVES).