UA140088U - 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 - with the help of substitution blocks (S-blocks); permutation - by means of blocks of mixing of cubes (P-blocks); SlidCode functional operations - 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). 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. Functional operations of substitution 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 (SlidCode).

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.

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 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 analog, 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 (reptyshyop) using blocks mixing of cubes (ReptiyaZ3O blocks); substitution (5!Irziyshiop) using substitution blocks (5-blocks); functional operations of cyclic shift and addition modulo 2 (5pPShNOmMm) 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 a 5-block form a variable three-dimensional matrix of substitutions, which is constructed by obtaining the multiplicatively inverse element x" over the extended finite Galois field CE(29) and by performing the affine transformation y-M :x"D over the primitive Galois binary field CE(2), while variable inverse symmetric matrices are used as the matrix 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 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 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 substitution and sliding coding of information data in three-dimensional space, and that the functional operations of substitution 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 (ZPyAOm), shuffling (reptshayop), substitution (zirviyshiop), functional operations of sliding coding (51IiaSode).

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 modulo 2 (ZpПИЙНОмы) - by with the help of appropriate devices, substitution (ziYiB5iyshiop) - with the help of substitution blocks (5-blocks); mixing (reptiiaiop) - with the help of cubes mixing blocks (P-blocks); functional operations of sliding coding (5IiYa4Sode) - with the help of mixed Gray codes, 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 they form a variable three-dimensional substitution matrix, which is built by obtaining a multiplicative inverse element x" over the extended finite Galois field SBB(23) and by performing the affine transformation y-M:x'-8 over the primitive binary Galois field CE(2), while variable inverse symmetric matrices are used as the matrix M of the affine transformation according to the value of the cyclic key, and that the functional operations of substitution 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 modulo 2 (5pPShNOmM), shuffling ( reptshaiyop), substitution (5!yB5iyshiop), functional operations of sliding coding (51IiaSoavier).

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 substitution 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 (ZPISHNOMm) - with the help of appropriate devices, substitution (vybyyshiop) - with the help of 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), while as a symmetric matrix M affine transformation uses variable inverse symmetric matrices, which are chosen according to the value of the cyclic key, and that the functional operations of substitution 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 modulo 2 (Z5pPShNOm), shuffling (reptshaiiop), substitution (5!yB5iishiop), 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 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 (remaining 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 manage the process of substitution and sliding coding of information data in three-dimensional space.

Sources:

AND "RIRB ROV 46-3" GEOEVAI IMEOVMATIOM RAVOSEBZ5IMa Z5TAMOANVOV 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 (с09С 1/00 (2015.01). Method of cryptographic transformation of information / Biletskyi A.Ya., Navrotskyi D.O.; applicant and the patent holder is the National Aviation University - ME 201404060; application 04/16/2014; published 06/25/2015, Mo 12.-5 b.

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) - with the help of 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 (5iIiaiSode) - with the help of mixed Gray codes, which differ in 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"--8 over the primitive binary Galois field C(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 that the functional operations of substitution 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 modulo 2 (5PyNVoOm), shuffling (reptiiaiop) , substitution (vyrviyshiop), functional operations of sliding coding (51IiySoavye).