The objective need to improve information security systems in the conditions of information-telecommunication technologies developing is shown. A new area of NP-complete promplems of diophantine analisys is firstly researched, namely Tarry–Escott multigrade diophantine equation systems (MDES) of given dimension and degree. The theorems, that describe parametrical MDES parametric solution properties, required for the development of the algorythm of building of dissymmetric bigram cryptosystem, are given in the article. The author's theorem, which allows to develop information protection system (IPS) mathematical model as a cortege, containing diophantine probleme. A new approach to develop dissymmetric bigram cryptosystem(DBC) on the base of two-parametrical MDES solution, which generalize open key cryptosystem, is considered. Forward and reverse conversions based on parametrical solution are suggested tyo realize on such algorythm. A new concept of equivalence of ordered sets of numbers (parameters) of a given dimension and order is introduced to build DBC mathematical model, using two-parametrical MDES solution. Described mathematical model demonstrates application potential of diophantine equations for IPS with a high degree of reliability.

Keywords: NP-complete probleme, information protection system, symmetric (dissymmetric) cryptosystem, open key cryptosystem, forward and reverse information conversions, Tarry–Escott multigrade diophantine equation system, parametrical solution

The sensor design on surface acoustic waves (SAW), representing the delay line with unidirectional inter-digital transducers (IDT) is considered. The factor of reflection of SAW from the unidirectional IDT loaded on impedance depending on value of resistance connected to it is investigated. On dependence of factor of reflection on size of resistance there is almost linear site at values of resistance more than 50 Ohm. The new design of the connected lattices of nanowire of zinc oxide, having the general resistance in a range of 50-250 Ohm which is connected to reflective IDT as loading is developed.

Keywords: passive sensors, ZnO nanowire, surface acoustic waves, interdigital transducer.