Security Aspects in Verification of the Safety Integrity Level of Distributed Control and Protection Systems

摘要

The article addresses some important issues of the functional safety analysis, namely the safety integrity level (SIL) verification of distributed control and protection systems with regard to security aspects. A quantitative method for SIL (IEC 61508) verification, based on so called differential factors, is presented. Taking into account SIL and the evaluation assurance level (EAL), which concerns the level of information security within entire system, two parametrical criterion function is defined for the SIL verification.