IEC 62443
IEC 62443 is the international standard series for securing industrial automation and control systems (IACS). It defines zones and conduits, Security Levels 1 to 4, and requirements for asset owners, integrators and product suppliers. IEC 62443-3-3 sets system-level security requirements and is widely applied to rail.
How it works
The series is organized into parts covering general concepts, policies and procedures, system requirements and component requirements. IEC 62443-3-2 defines how to partition a system into security zones and the conduits between them and to assign each zone a target Security Level (SL-T). IEC 62443-3-3 lists the system requirements needed to achieve each level across seven foundational requirements, from identification and authentication to resource availability.
Component-level parts (62443-4-1 and 4-2) address the secure development lifecycle and technical requirements for individual products.
Why it matters for security
IEC 62443 is the common language for OT security across industries and the basis that rail-specific standards such as CENELEC TS 50701 and IEC 63452 build on. Rail operators use its zone-and-conduit model to design segmentation and its Security Levels to specify requirements to suppliers; automated checks against 62443-3-3 are a practical way to evidence compliance.
Related solution
Aligning rail OT security with IEC 62443-3-3
Rail-aware support for zones and conduits, mapping real OT communications to validate security design.
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