IEC 62443

IEC 62443 is an international standard series for securing industrial automation and control systems throughout their entire lifecycle, from design through decommissioning. It was originally developed by ISA (through its ISA99 committee) and later adopted and extended by the IEC. The series is organized into parts covering general concepts and terminology, organizational policies and procedures, system-level requirements (including the zone and conduit model), and component-level requirements, and it defines a scale of Security Levels (SL 0 through 4) describing how well protected a system is against increasingly capable attackers.