NIST Special Publication 800-171, published by the National Institute of Standards and Technology (NIST), addresses the protection of Controlled Unclassified Information (CUI) within nonfederal information systems and organizations. The document outlines the need for safeguarding sensitive information that, while not classified, is subject to legal or regulatory controls for dissemination and protection. This is of critical importance to federal agencies, as the security of CUI in nonfederal environments—such as those owned or operated by federal contractors, state and local governments, and academic institutions—can have a direct impact on the federal government's operational effectiveness and mission success.
The publication specifies recommended security requirements for protecting the confidentiality of CUI, particularly when specific safeguarding mandates do not already exist. These requirements apply to pertinent system components involved in processing, storing, or transmitting CUI. NIST draws from established federal standards (FIPS 200 and NIST SP 800-53), tailoring them to omit requirements that are uniquely federal, not confidentiality-related, or routinely satisfied by nonfederal entities. The framework encompasses fourteen security families, such as access control, incident response, and system integrity, with a structured approach dividing controls into basic and derived requirements. The document further provides mapping to international standards (ISO 27001) and guidance on tailoring controls, ensuring nonfederal organizations can implement alternative, equally effective measures to meet security objectives, while highlighting the national imperative of safeguarding controlled information outside of federal systems.
