A timestamping service is a system that issues verifiable proof that a piece of data existed at or before a particular time, often using cryptographic methods.
Semantic Classification
Content
- A timestamping service receives a hash of a document and returns a signed token binding that hash to a time value. Anyone can later verify that the document existed at the recorded time without revealing the document itself.
- Centralised services follow the RFC 3161 standard with a trusted authority, while blockchain-based timestamping anchors a hash in a public ledger so the existence proof relies on the immutability of the chain rather than a single authority.