How does ProofMark different from other trusted time stamping solutions?

Up until now, most digital timestamping systems have had to rely upon external Time Stamping Authorities (TSAs) to "vouch" for time. The Internet's RFC 3161 X.509 Public Key Infrastructure Time-Stamp Protocol is an example of these older systems. External TSAs can be expensive and unreliable, since they are run by third parties outside your organization. More importantly, such systems suffer from a single point of catastrophic failure: if the TSA’s private key is ever compromised, then none of the timestamps ever issued by that TSA can ever be trusted again.

The ProofMark System works in a fundamentally different way, which does not rely on external Time Stamping Authorities. Your ProofMark server is always under your control. And unlike RFC 3161 systems, the ProofMark System does not suffer from a single point of failure - the accidental compromise of any one private key does not invalidate all timestamps ever issued.