Time Stamp Protocols - The PKIX document describes a Time Stamp Authority (TSA) and a Temporal Data Authority (TDA), and the protocols to be used to communicate with them.

Digital Signature software and Timestamp Authority. A time stamp is like a digital notary from a trusted third-party for protecting intellectual property and copyright protection. Uses PKIX electronic signature standards. Runs on Windows, Macintosh, Linux, Solaris, Java. International