Practical problems within safety related cryptography communication systems assessment for safety critical applications

Abstract

The authors of this article are focus on the analysis of safety-related (SR) communication system with open transmission system for safety-related applications with increasing SIL (Safety Integrity Level). The main part is orientated to summarization of practical problems within safety assessment of communications on the base of mathematical model of SR communication with using cryptography code of several lengths for keeping of message confidentiality and integrity, which is transmitted across open communication channel. The experimental part analyses SR communication in the end-to-end (between two nodes), with assumption of using cryptography and safety codes. Obtained results of probability of error of cryptography code are determined for model of BSC (Binary Symmetric Channel). In addition the cryptography degradation of block cryptography codes with using digital modulation techniques are discussed.