The information security is playing an incre- asingly important role nowadays. Therefore, virus can be transmitted through the information in encrypted form. This is also applied to embedded systems. In this regard, the article is assigned to the topic of cryptocurrency pro- tection in embedded systems. The article is focused on the algorithm of symmetric block transformation "Kalyna".
The Gao approach to construction of high order elements in arbitrary finite fields is to choose a convenient polynomial, which defines an extension of an initial prime field. This choice depends on one polynomial-parameter. That is why the mentioned approach can be considered as using of a finite field description with one degree of freedom. We explore in the paper the possibility of improvement of lower bound on element orders in finite fields of general form with using of two degrees of freedom.
We have performed computer calculations in Maple environment for verification of Gao assumption for finite fields of characteristic 2, 3, 5 and presented correspondent results. If the assumption is true, then it is possible to construct explicitly in these fields in polynomial time elements of high multiplicative order that are used in cryptography (Diffie-Hellman protocol, El-Gamal public key cryptosystem, El-Gamal digital signature).
Theoretical and practical aspects of analysis and synthesis of perspective symmetric cryptosystems have been developed. Analysis of requirements for perspective symmetric cipher, in particular for cryptoresistability, operating speed and memory volume has been performed. Principles of synthesis of the modern block symmetric cryptographical transformations have been investigated, main results of the performed investigations have been presented.