Security and functional safety - Differing requirements and related goals

Measures of functional safety and security often have similar goals, so that solutions for both domains can overlap. For instance, security measures are necessary for safety functions if they are vulnerable via public networks. However, requirements differ considerably between intelligent attacks on security on the one hand and random or systematic faults and human errors of functional safety on the other hand. In this article, besides a description of both functional safety and security for automation, we describe the relationships between their goals such that structured and efficient solutions will be possible. For their evaluation, we propose common metrics for both domains.