Determination of Error Probability of Cryptography and Safety Codes for Safety-Related Railway Applications

The paper deals with the problem of determination of error probability of cryptography and safety codes used within the safety-related railway applications with increasing safety integrity level (SIL). In the paper are also described requirements for cryptographic block code and safety linear block code in safety-related communications for railway application. The main part is oriented to the description of mathematical apparatus for the error probability of the cryptography and safety block codes for communication between two safety-related devices across GSM-R communication channel. The practical results are related to the quantitative evaluation of an average error probability of the cryptography and safety codes for several lengths of safety-related messages which are expanded about determination of the cryptography degradation with using GMSK modulation scheme.