# Common Access Card The Common Access Card (CAC) is the U.S. Department of Defense smart identity credential used for physical and logical access by eligible personnel. ## Notebook evidence PDF page 12 of [[Scanned_20260730-1845]] encloses `CAC`, `ECA`, and `PIV` as related identity systems. The page compares credential ecosystems: CAC as a DoD-issued credential, PIV as the broader federal standard, and ECA as certificate access for eligible external parties. ## Boundary The notation documents research. It does not establish eligibility, issuance, possession, access to a protected system, or a relationship with the Department of Defense. ## Relationships [[External Certification Authority]] · [[Personal Identity Verification]] · [[Public-Key Infrastructure]] · [[Digital Identity]] ## Source - [[Scanned_20260730-1845]], PDF page 12.