or other departments within the DoD or the USCG. For retired U.S. military personnel who subsequently become DoD or USCG civilians or DoD or USCG contractors, the DoD ID/EDIPI Number on their CAC will be the same as on their DD Form 2 Retired ID Card. For non-military spouses, unremarried former spouses, and widows/widowers of active, Reserve or Retired U.S. military personnel who themselves become DoD or USCG civilians or DoD or USCG contractors, the DoD ID/EDIPI Number on their CAC will be the same as on their DD 1173 Uniformed Services Privilege and Identification Card (e.g., Dependent ID card). The front of the CAC is fully laminated, while the back is only laminated in the lower half (to avoid interference with the magnetic stripe). The CAC is said to be resistant to identity fraud, tampering, counterfeiting, and exploitation and provides an electronic means of rapid authentication. There are currently four different variants of CACs. The Geneva Conventions Identification Card is the most common CAC and is given to active duty/reserve armed forces and uniformed service members. The Geneva Convention Accompany Forces Card is issued to emergency-essential civilian personnel. The ID and Privilege Common Access Card is for civilians residing on military installations. The ID card is for DOD/Government Agency identification for civilian employees. Encryption Until 2008, all CACs were encrypted using 1,024-bit encryption. Starting 2008, the DoD switched to 2,048-bit encryption. Personnel with the older CACs had to get new CACs by the deadline. On October 1, 2012, all certificates encrypted with less than 2,048-bits were placed on revocation status, rendering legacy CACs useless except for visual identification. Usage The CAC is designed to provide two-factor authentication: what you have (the physical card) and what you know (the PIN). This CAC technology allows for rapid authentication, and enhanced physical and logical security. The card can be used in a variety of ways. Visual identification The CAC can be used for visual identification by way of matching the color photo with the owner. This is used for when the user passes through a guarded gate, or purchases items from a store, such as a PX/BX that require a level of privileges to use the facility. Some states allow the CAC to be used as a government-issued ID card, such as for voting or applying for a drivers license. Magnetic stripe The magnetic stripe can be read by swiping the card