IEC 62443-3-3:2013 pdf download,Industrial communication networks – Network and system security – Part 3-3: System security requirements and security levels.

IEC 62443-3-3:2013 specifies system security requirements (SRs) for industrial automation and control systems (IACS). It translates the series’ high-level foundational requirements (FRs) into concrete security capabilities for an entire control-system environment, so organizations can reach a chosen target security level.

The standard is closely linked to the IEC 62443 security levels (SLs) model and uses security level ratings per requirement. It defines a set of seven foundational requirements (FR1–FR7) that cover key security objectives: identification and access control (FR1), use control (FR2), system integrity (FR3), data confidentiality (FR4), restricted data flow (FR5), timely response to events (FR6), and resource availability (FR7). For each FR, IEC 62443-3-3 defines associated system requirements and shows how these map to Security Levels 0 through 4, representing increasing attacker capability and likelihood.

In practice, IEC 62443-3-3 is used alongside the “zones and conduits” architecture concept: assets are grouped into zones with homogeneous security needs, and conduits provide controlled communication between zones. The result is a structured way to design, implement, and validate IACS defenses against cyber threats by specifying what the system must be able to do, and at what assurance level.