UA115523U - METHOD OF CRYPTOGRAPHICAL TRANSFER 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 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 shifting and addition modulo 2 (ShiftRow) operations using appropriate devices. The bit blocks of the information sequence are presented in the form of three-dimensional matrices (cubes), as the S-block form a variable three-dimensional matrix of substitutions, which is constructed by obtaining a multiplicative inverse element over the extended Galois finite field GF (2), and perform affine transformation over G 2). In this case, the inverted symmetric matrices, which are chosen according to the value of the cycle key, are used as matrices Μ of the affine transformation, and the functional operations of substitution are not fixed, but depend on the state of the key, and functional operations of the cyclic shift are not fixed, but depend on the state of the key.

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) - 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 to the declared useful model, chosen as the closest analogue, 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 (regtshiiaiiiop) - according to using cubes mixing blocks (ReptiyaZ30 blocks); substitution (zyb5iyshiop) - using substitution blocks (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, and are constructed by obtaining the multiplicative inverse element X over the extended finite Galois field CE(28) and by performing the affine transformation UMH B over the primitive binary Galois field CE(2), while variable inverse symmetric matrices are used as matrices M of the affine transformation, which

Zo is chosen 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 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, while the substitution parameters change dynamically depending on the state of the key and the cyclic shift parameters dynamically change depending on the state of the key.

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: shuffling (reptiiaiiop) - 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 (ZNSCHNOm) - with the help of appropriate devices, according to a useful model, 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 substitution matrix, which is constructed by obtaining multiplicatively of the inverse element X over the extended finite Galois field C1B(25) and by performing an affine transformation

UMx B over the primitive Galois binary field CE(2), while variable inverse symmetric matrices are used as the matrices M of the affine transformation, which are chosen according to the value of the cyclic key, and the functional operations of substitution are not fixed, but depend on the state of the key, and the functional operations of 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 and dynamically control the process of substitution and cyclic shift of information data.

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: shuffling (regtshiiyaaiyop) - with the help of cube shuffling blocks (P-blocks); substitution (5!Ir5iyshiop) - using blocks of substitutions (5-blocks); functional operations of cyclic shift and addition according to module 2 (ZPSHAOM) - with the help of appropriate devices. 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 SI (28) and by performing the affine transformation (1) over the primitive binary field Galois SI(2), while as a symmetric matrix M of the affine transformations use variable inverse symmetric matrices that are chosen according to the value of the cyclic key and the functional operations of shuffling are not fixed but depend on the state of the key, and the functional operations of cyclic shift 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, accordingly, dynamically control the process of shuffling information data and dynamically control the process of cyclic shifting of information data.

Depending on the state of the round key, the shuffling and cyclic shift parameter is selected by adding modulo 2 all the 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 the 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 substitution matrices and different shift values 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 substitution process and 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. pErulymly. emeguzres.sot/MIZT/MIZT-RIRB/dompiosaya. ryr"zres-BIR5 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 (zibv5iyshiop) - using substitution blocks (5 blocks); functional operations of cyclic shift and addition according to module 2 (ZPSHNVOmU) - with the help of appropriate devices, 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 built by obtaining the multiplicative inverse element X over the extended finite Galois field CE(23) and by performing the affine transformation UMH B 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 value of the cyclic of the key, and that the functional substitution operations are not fixed but depend on the state of the key, and that the functional operations of cyclic shifting are not fixed but depend on the state of the key.