GENERATING A SEQUENCE OF ASYMMETRIC CET OPERATIONS WITH AN ACCURACY OF UP TO THE PERMUTATION OF THE SECOND OPERAND

Abstract

The article is devoted to the construction of asymmetric CET operations suitable for cryptographic information transformation, namely CET encryption. The use of CET operations in the construction of streaming ciphers guarantees bidirectional transmission of information between subscribers. The specific feature of asymmetric CET operations is that they provide different ciphers in the process of encrypting the same information using the same key sequences. To improve stream ciphers, it is of great importance to be able to use several asymmetric two-operand CET operations with the same properties instead of one. That is why the problems of synthesizing groups of CET operations with permutation accuracy are extremely relevant. After all, their solution will allow us to build generators of pseudo-random sequences of CET operations with the same properties to ensure the construction of new generation of cryptographic algorithms of stream encryption. The purpose of the article is to study the possibility of using the method of generating groups of asymmetric CET operations with an accuracy of up to the permutation of the second operand to build low-resource asymmetric stream encryption systems. Methodology. The paper shows that it is expedient to generate groups of operations of strictly stable coding on the basis of modifying the CET operation of strictly stable coding with an accuracy of permutation of the second operand. To synthesize models of CET operations, both direct and reverse, one of the ways to implement their construction method is presented, which consists in generating a sequence of asymmetric two-operand CET operations with an accuracy of permutation of the second operand. The correctness of the obtained models for the synthesis of groups of direct and reverse asymmetric two-operand CET operations is verified on specific examples, which is confirmed by the results of a computational experiment for 2Ci-quantum asymmetric two-operand CET operations. In the course of the study, the methods and principles of information and coding theory, Boolean algebra, discrete mathematics, the theory of synthesis and modeling of operations, and cryptography were used. Scientific novelty. The scientific novelty of the work is to analyze the practical aspects of using groups of asymmetric CET operations with an accuracy of up to the permutation of the second operand to build low-resource cryptography algorithms by ensuring the generation of direct and reverse asymmetric two-operand CET operations by using only direct one-operand CET operations, which significantly reduces the complexity of the cryptographic algorithm and the complexity of the cryptographic system implementation. Conclusion. As a result of the study, the following was found: all asymmetric CET operations belonging to the synthesized group with an accuracy of up to the permutation of the second operand have the same cryptographic properties, since they implement the same sets of substitution tables in the same way by chance; the ability to generate groups of forward and reverse asymmetric CET operations with an accuracy of up to the permutation of the second operand on the basis of any two-operand CET operation will provide both encryption and decryption of information for building streaming encryption systems.