What defines the select and categorize steps of RMF for National Security Systems?

The select and categorize steps of the Risk Management Framework (RMF) for National Security Systems are defined by CNSS Instruction 1253. This document specifically lays out the processes for managing risk in national security systems, emphasizing the unique requirements and sensitivities linked to national security.

In the context of the select and categorize steps, CNSS Instruction 1253 outlines how to identify and categorize the information systems based on their security needs and impact levels. This is crucial as it sets the stage for subsequent steps in the RMF, ensuring that systems are effectively classified and prioritized according to their importance to national security and the potential impact of a security breach.

Other documents, such as FIPS 199 and FIPS 200, provide guidance on security categorization and the minimum security requirements for federal information systems respectively, but CNSS Instruction 1253 takes precedence in defining the RMF related to national security contexts, making it the most relevant reference in this scenario. NIST 800-30, while important for risk assessments, does not specifically address the select and categorize steps in the same manner.