Cryptographically secure identity certificates

We present FACECERTS, a simple, inexpensive, and cryptographically secure identity certification system. A FACECERT is a printout of person´s portrait photo, an arbitrary textual message, and a 2D color bar-code which encodes an RSA signature of the message hash and the compressed representation of the face encompassed by the photo. The signature is created using the private key of the party issuing the ID. Verification is performed by a simple, intelligent, and off-line scanning device that contains the public key of the issuer. The system does not require smart cards. More interestingly, the ID does not need to be printed by a high-end printer, it can be printed anywhere. We present a novel algorithm for compressing faces and investigate the reliability of the crucial components of the system.