IEC 62443-3-3 (2013)

IEC 62443-3-3:2013 is a normative standard in the IEC 62443 series that specifies system security requirements and defines four security levels (SL 1 to SL 4) for industrial automation and control systems (IACS). Published by the International Electrotechnical Commission (IEC), it translates the foundational requirements of the series into detailed system level requirements that can be assigned a target security level based on the threats a system must withstand.

The document organises requirements around foundational requirement groups such as identification and authentication, use control, system integrity, data confidentiality, restricted data flow, timely response to events, and resource availability. It is used by integrators and asset owners to specify and verify the security capability of a control system as a whole, complementing the component level requirements found in IEC 62443-4-2.