In this fashion you can prove that you had possession of a particular document at a particular time. For example if someone sends you some information and you want to later prove that you had it before a certain date, send a copy through the TimeStamp service. If you are concerned about the confidentiality of the document, you don't need to send the the whole thing. Just send an MD5 hash code of the document (programs do create MD5 hash codes are available on the net) *or* send a PGP detached signature.
The timestamp will demonstrate that we (the TimeStamp service operators) assert that you sent it through our server at a particular time (and therefore had to have it in hand prior to that time). Because we are a third party, not related to you or to whomever sent you the information, our opinion will have some value.
For security reasons we will periodically change the TimeStamp service key. All TimeStamp service public (PGP) keys will be available either via e-mail or via the Web (found through this page).
Note: This will start off as an experimental service. We will not assert anything from a legal standpoint. I.e., initially we will offer this service with NO WARRANTY on an AS IS basis. However we will use our best reasonable efforts to not screw up!