NIST Special Publication 800 -172 Enhanced Security Requirements for Protecting Controlled Unclassified Information A Supplement to NIST Special Publication 800- 171 RON ROSS VICTORIA PILLITTERI GARY GUISSANIE RYAN WAGNER RICHARD GRAUBART DEB BODEAU This publication is available free of charge from: https://doi.org/10.6028/NIST.SP.800- 172 NIST Special Publication 800 -172 Enhanced Security Requirements for Protecting Controlled Unclassified Information A Supplement to NIST Special Publication 800- 171 RON ROSS VICTORIA PILLITTERI Computer Security Division National Institute of Standards and Technology GARY GUISSANIE RYAN WAGNER Institute for Defense Analyses RICHARD GRAUBART DEB BODEAU The MITRE Corporation This publication is available free of charge from: https://doi.org/10.6028/NIST.SP.800-172 February 2021 U.S. Department of Commerce Wynn Coggins, Acting Secretary National Institute of Standards and Technology James K. Olthoff, Performing the Non-Exclusive Functions and Duties of the Under Secretary of Commerce for Standards and Technology & Director, National Institute of Standards and Technology NIST SP 800- 172 ENHANCED SECURITY REQUIREMENTS FOR PROTECTING CUI _________________________________________________________________________________________________ i This publication is available free of charge from: https://doi.org/10.6028/NIST.SP.800 -172 Authority This publication has been developed by NIST to further its statutory responsibilities under the Federal Information Security Modernization Act (FISMA), 44 U.S.C. § 3551 et seq. , Public Law (P.L.) 113 -283. NIST is responsible for developing information secu rity standards and guidelines, including minimum requirements for federal information systems, but such standards and guidelines shall not apply to national security systems without the express approval of the appropriate federal officials exercising polic y authority over such systems. This guideline is consistent with requirements of the Office of Management and Budget (OMB) Circular A -130. Nothing in this publication should be taken to contradict the standards and guidelines made mandatory and binding on federal agencies by the Secretary of Commerce under statutory authority. Nor should these guidelines be interpreted as altering or superseding the existing authorities of the Secretary of Commerce, OMB Director, or any other federal official. This publicat ion may be used by nongovernmental organizations on a voluntary basis and is not subject to copyright in the United States. Attribution would, however, be appreciated by NIST. National Institute of Standards and Techn ology Special Publication 800 -172 Natl. Inst. St and. Technol. Spec. Publ. 800 -172, 84 pages (February 2021 ) CODEN: NSPUE2 This publication is available free of charge from: https://doi.org/10.6028/NIST.SP.800- 172 Comments on this publication may be submitted to: National Institute of Standards and Technology Attn: Computer Security Division, Information Technology Laboratory 100 Bureau Drive (Mail Stop 8930) Gaithersburg, MD 20899 -8930 Email: [email protected] All comments are subject to release under the Freedom of Information Act (FOIA) [FOIA96 ]. Certain commercial entities, equipment, or materials may be identified in this document to describe an experimental procedure or concept adequately. Such identification is not intended to imply recommendation or endorsement by NIST, nor is it intended to imply that the entities, materials, or equipment are necessarily the best available for the purpose. There may be references in this publication to other pu blications currently under development by NIST in accordance with its assigned statutory responsibilities. The information in this publication, including concepts, practices, and methodologies, may be used