Timestamping

Timestamping is the act of recording the exact date and time that a piece of data existed or an event happened, in a way that can be trusted and checked later. A trusted timestamp proves a document was in a certain state at a certain moment, not backdated afterwards.

It is like a post office date stamp on an envelope, giving independent proof of when something was sent. Timestamping matters because being able to show that a record, an agreement or a piece of evidence existed at a given time is often as important as the record itself.