4 services carry this tag in their source record. Tags come from the provider, not from us — a tag is a claim about what the service does, not proof that it does it well.
Timestamp SHA-256 hashes in Bitcoin with OpenTimestamps: returns a standard .ots proof per hash (pending, complete within hours), verifiable without us
Timestamp and notarize any file or data by its SHA-256 hash: blockchain proof of existence and document integrity, anchored on Polygon in minutes and attested on Bitcoin (OpenTimestamps); blockchain notarization, not a n...
Proof of existence on the IOTA mainnet: send text, a SHA-256 hash or a URL and get a tamper-proof timestamp. We store only the SHA-256 (never your content) in a locked notarization of the official IOTA Notarization packa...
Timestamp anything on Bitcoin with OpenTimestamps: send text, a SHA-256 hash or a URL and get a standard .ots proof (base64). Only a salted hash leaves our server. The public calendars anchor it in a Bitcoin block within...