Information Security Oversight Office (ISOO)

Frequently Asked Questions on Incidents and Spills

National Security Systems

Question #1 - What is a "national security system" (NSS)?

A: Title 44, U.S. Code Section 3542 (b)(2), Federal Information Security Management Act (FISMA), Title III, Public Law 107-347, December 17, 2002, defines a "national security system" as follows:

  1. Any information system (including any telecommunications system) used or operated by an agency or by a contractor of any agency, or other organization on behalf of an agency, the function, operation, or use of which:
    1. Involves intelligence activities;
    2. Involves cryptologic activities related to national security;
    3. Involves command and control of military forces;
    4. Involves equipment that is an integral part of a weapon or weapon system; or
    5. Subject to subparagraph [provided below], is critical to the direct fulfillment of military or intelligence missions; or is protected at all times by procedures established for information that have been specifically authorized under criteria established by an Executive Order or an Act of Congress to be kept classified in the interest of national defense or foreign policy.

Question #2 Where can I get additional information on the NSS, incidents, and spills?

A: Please visit:

Question #3 How can I contact the CNSS?

Contact the CNSS Secretariat via:

CNSS Secretariat - National Security Agency
9800 Savage Road STE 6165
Ft Meade MD 20755-6165


  • Electronic mailing address of -
  • Office number - (410) 854-6805
  • Secure Telephone Equipment (STE) - (410) 854-0217
  • Unclassified Facsimile - (410) 854-6814
  • CNSS Home Page-