The Common Access Card, also commonly referred to as the CAC, is a smart card about the size of a credit card. It is the standard identification for Active Duty United States Defense personnel, to include the Selected Reserve and National Guard, United States Department of Defense (DoD) civilian employees, United States Coast Guard (USCG) civilian employees and eligible DoD and USCG contractor personnel. It is also the principal card used to enable physical access to buildings and controlled spaces, and it provides access to defense computer networks and systems. It also serves as an identification card under the Geneva Conventions (especially the Third Geneva Convention). In combination with a personal identification number, a CAC satisfies the requirement for two-factor authentication: something the user knows combined with something the user has. The CAC also satisfies the requirements for digital signature and data encryption technologies: authentication, integrity and non-repudiation. The CAC is a controlled item. As of 2008, DoD has issued over 17 million smart cards. This number includes reissues to accommodate changes in name, rank, or status and to replace lost or stolen cards. As of the same date, approximately 3.5 million unterminated or active CACs are in circulation. DoD has deployed an issuance infrastructure at over 1,000 sites in more than 25 countries around the world and is rolling out more than one million card readers and associated middleware. Issuance The CAC is issued to Active United States Armed Forces (Regular, Reserves and National Guard) in the Department of Defense and the U.S. Coast Guard; DoD civilians; USCG civilians; non-DoD/other government employees and State Employees of the National Guard; and eligible DoD and USCG contractors who need access to DoD or USCG facilities and/or DoD computer network systems: Active Duty U.S. Armed Forces (to include Cadets and Midshipmen of the U.S. Service Academies) Reserve members of the U.S. Armed Forces National Guard (Army National Guard and Air National Guard) members of the U.S. Armed Forces National Oceanic and Atmospheric Administration United States Public Health Service Emergency-Essential Employees Contingency Contractor Employees Contracted college & university ROTC Cadets and Midshipmen Deployed Overseas Civilians Non-Combatant Personnel DoD/Uniformed Service Civilians residing on military installations in CONUS, Hawaii, Alaska, Puerto Rico, or Guam DoD/Uniformed Service Civilians or Contracted Civilian residing in a foreign country for at least 365 days Presidential Appointees approved by the United States Senate DoD Civilian employees, and United States Military