Information operations · Cybersecurity · cyberwar · Information Warfare

National Security Archive: Cyber Glossary

The Cyber Glossary is a compilation of specialized terms to help experts and the public alike navigate the complex field of cybersecurity. This resource combines definitions from a variety of government compilations.  Sources for each entry – often multiple definitions exist – are provided, as is a key to allow for further research.  This list will be expanded regularly. Reader suggestions are welcome.

Click on the appropriate letter in the left column or type a word or phrase in the search box at the top right of this page.



Access Point – A device that logically connects wireless client devices operating in infrastructure to one another and provides access to a distribution system, if connected, which is typically an organization’s enterprise wired network. (From: SP 800-48; SP 800-121) (NICSS 7298 Revision 2)

Accounting Legend Code (ALC) – Numeric code used to indicate the minimum accounting controls required for items of accountable communications security (COMSEC) material within the COMSEC Material Control System. SOURCE: CNSSI-4009 (NICCS)


False Acceptance Rate (FAR) – The probability that a biometric system will incorrectly identify an individual or will fail to reject an impostor. The rate given normally assumes passive impostor attempts. SOURCE: SP 800-76

The measure of the likelihood that the biometric security system will incorrectly accept an access attempt by an unauthorized user. A system’s false acceptance rate typically is stated as the ratio of the number of false acceptances divided by the number of identification attempts. (CNSSI-4009) (NISTIR

Federal Bridge Certification Authority Membrane – The Federal Bridge Certification Authority Membrane consists of a collection of Public Key Infrastructure components including a variety of Certification Authority PKI products, Databases, CA specific Directories, Border Directory, Firewalls, Routers, Randomizers, etc. (SP 800-32) (NISTIR)