Patent ID: 7731435

Claim:
A method for printing an electronic document comprising: a first computer system receiving from a second computer system, separate from the first computer system, a communication to print a document; transmitting to the second computer system fingerprint data for at least a first sheet of printable media on which the document is to be printed, the fingerprint data based on data obtained from intrinsic structure of the first sheet of printable media; receiving from the second computer system encrypted fingerprint data and a first decryption key, the encrypted fingerprint data comprising an encrypted form of the fingerprint data produced by the second computer system, the first decryption key suitable for decrypting the encrypted fingerprint data to thereby recover the fingerprint data; and printing the document on the first sheet of printable media, including transferring machine readable information to the first sheet of printable media, wherein the encrypted fingerprint data and the first decryption key can be obtained from the machine readable information.