UA18442U - Method of the cryptographic transformation of information - Google Patents

Abstract

The proposed method of the cryptographic transformation of information consists in presenting the information as 128-bit data blocks and performing the iterative processing of the data blocks by simple operations of cryptographic transformation, such as operations of mixing columns, substitution, cyclical shift, and modulo 2 addition. As the parameters of cyclical shift, variables are used that are selected according to the values of the cryptographic key.

Description

Description of the invention

The proposed useful model refers to the field of cryptographic protection of information and can be used in encryption tools in information processing systems to expand their capabilities.

There is 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 (regtiiayop) - using permutation blocks (P-blocks); substitution (zirziyshiop) - with the help of substitution blocks (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, which provide the necessary conditions for the stability of the cryptographic transformation.

The disadvantage of this method is that at each iteration of the cryptographic transformation of information, a cyclic shift operation is performed for a fixed number of symbols, which does not allow to flexibly change the parameters of cryptographic processing 12 and dynamically control the cyclic shift process.

The closest to the proposed technical solution, chosen as a prototype, is an improved method of cryptographic transformation |2), which is based on the fact that the information sequence is presented in the form of 128-bit blocks, which are subject to iterative processing by primitive cryptographic transformations: mixing (those) - by using column mixing blocks (MixSoYShtp blocks); substitution (zirziyshiop) - with the help of substitution blocks (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, which provide the necessary conditions for the stability of the cryptographic transformation.

At each iteration of the cryptographic transformation, the processed data is presented in the form of an array of 4 x 4 bytes dv (see Table 1). shh ooh here ooh wo. vno schu yu sot vot go go h

When performing a cyclic shift operation, the last three rows of the array from table 1 are cyclically shifted by a fixed number of bytes: the second row is shifted by one byte, the third by two bytes, the fourth by three bytes (see c from table 2). "- vsovotvovoy 00000000 vooivotvohivov, ato|at1| ag (a13 am1 ai2|aiz ato « - s y?

AND

- (ee) pi The disadvantage of the prototype method is that at each iteration of the cryptographic transformation of information, a cyclic shift operation is performed for a fixed number of symbols, which does not allow to flexibly change the cryptographic processing parameters and dynamically control the cyclic shift process. d" The useful model is based on the task of creating a method of cryptographic transformation of information, which, due to the changing parameters of the cyclic shift at each iteration of the cryptographic transformation, will make it possible to flexibly change the parameters of cryptographic processing and dynamically control the cyclic shift process. 99 The problem is solved by using variable c values as parameters of the cyclic shift, which are chosen according to the values of the cyclic key.

The technical result that can be obtained by implementing a useful model consists in obtaining the ability to flexibly change the parameters of cryptographic processing and dynamically control the cyclic shift process at each iteration of the cryptographic transformation. because the essence of the proposed method of cryptographic transformation of information is that the information sequence is presented in the form of 128-bit blocks, which are subject to iterative processing by primitive cryptographic transformations: mixing (those) - with the help of column mixing blocks (MixSoYShtp blocks); substitution (zirziyshiop) - using substitution blocks (5-blocks); functional operations of cyclic shift and addition by modulo 2 - with the help of appropriate devices. At each iteration of the cryptographic transformation, the processed data is presented in the form of an array of 4 x 4 bytes. Over each row of the array, a cyclic shift operation is performed with variable parameters that are set according to the value of the cyclic key (see Table 3).

Table Z " "shtshtiek ato|ach1at2|a13 aiz ato|al1a12

AND

The cyclic key is generated from the encryption key using a 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 cyclic shift operation is performed with variable parameters that can be chosen from the 4-byte words of the extended key in an arbitrary way, for example, by using the first byte of the cyclic key. This makes it possible to flexibly change the cryptographic processing parameters and dynamically control the cyclic shift process during the cryptographic conversion process. So, for example, the rows of the array from table Z are cyclically shifted by the following number of bytes: the first row is shifted by two bytes, the second row Z is shifted by three bytes, the third by two bytes, the fourth by one byte. With a different value of the cyclic key, the cyclic shift parameters of the array will be different. Therefore, the proposed technical solution allows you to perform cryptographic transformation of data by flexibly changing the cyclic shift parameters at each iteration.

Zo and dynamically manage the iterative processing of information data.

Thus, due to the use as cyclic shift parameters of variable values, which are chosen from C in accordance with the values of the cyclic key, it is possible to flexibly change the cryptographic processing parameters and dynamically control the cyclic shift process at each iteration of the cryptographic transformation.

Sources of information: so 1. Myopa! Ipviyshe oi Biapdagaz apa Tesppoiodu, "RIRBZ-46-3: YuOaya Yeepsguriop Biapdaga Osi. 1999, p

Amayarieye ai per:/svgs.pivi dom/ribiisabyopelLirv/ NEr://svgo.pivi dom/ribiisaiopeL relay rz46-ZLirz46-3. heaven 2. Myopia! Ipviyshsche oi 5(apdagaz apa Tesppoiodu, "RIRB-197: Admapsedi Epsguriop Ziapdaga Mom. 2001.

Amayarie ai per://svgs.pivi dom/rybiisayopelLrv/ pEr://svgs. half house/ribiisabyopierre/Lirz. 197Lirvg-197. heaven "that

Claims (1)

The formula of the invention and . . . ш" - . сш . . и? The method of cryptographic transformation of information, which consists in the fact that the information sequence is presented in the form of 128 bit blocks, which are subject to iterative processing by primitive cryptographic transformations: mixing (thich) - using column mixing blocks (MixSoYshtp blocks ); substitution - (zirziyshiop) - using blocks of substitutions (5-blocks); functional operations of cyclic shift and addition modulo 2 - with the help of appropriate devices, which differs in that as parameters of the cyclic shift at each iteration of the cryptographic transformation, variables are used the values that are selected according to the values of the cyclic key. iz 70 pyaya i sche i : : o. Official Bulletin "Industrial Property". Book 1 "Inventions, useful models, topographies of integrated microcircuits", 2006, M 11, 15.11. 2006. State Department of Intellectual Property of the Ministry of Education and Science of Ukraine, 60 b5