The Common Access Card (CAC) is a Department of Defense (DoD) card used for authentication and access. According to the Defense Human Resource Activity (DHRA, n.d.):

The CAC, a "smart" card about the size of a credit card, is the standard identification for active duty uniformed service personnel, Selected Reserve, DoD civilian employees, and eligible contractor personnel. It is also the principal card used to enable physical access to buildings and controlled spaces, and it provides access to DoD computer networks and systems.

The CAC has a single integrated circuit chip (ICC) for the storage of data such as digital fingerprints and photos, Personal Identity Verification (PIV) certificate, agency and organizational affiliation (DHRA, n.d.). In addition, CACs enable the use of public key infrastructure (PKI) certificates, which enable the encryption and decryption of emails, the signing of digital documents, and the establishment of secure connections.

References

Defense Human Resource Activity (DHRA). (n.d.). Common access card (CAC). http://www.cac.mil/common-access-card/

Defense Human Resource Activity (DHRA). (n.d.). Common access card (CAC) security. http://www.cac.mil/common-access-card/cac-security/