Datum - Provides secure time management solutions that manage the integrity of time in digital business processes for the Information Technology market. www.datum.com/tt
Internet X.509 PKI - 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. www.imc.org/draft-ietf-pkix-time-stamp
Trusted third-party time authority - DigiStamp provides digital time stamps for e-commerce and intellectual property witnessing. www.digistamp.com
