Verify the archive
Every email, forum post and commit in Satoshi Mail has a fingerprint: a SHA-256 hash of its exact words, sender and date. The list of all 4,568 fingerprints is timestamped in the Bitcoin blockchain with OpenTimestamps, so anyone can prove each message existed, word for word, by that date, and hasn't been edited since.
Verify a message in Satoshi Mail
This version
Fingerprint: 1be6e97aff6888b573ce115df631fb2d5bb003075f941ed7c1111266a6c3cbef
Status: In Bitcoin block 972,522
Download the manifest · download the .ots proof
Every version
| Date | Fingerprint | Proof | Files |
|---|---|---|---|
| 2026-10-21 | 1be6e97aff6888b5… | In Bitcoin block 972,522 | manifest · .ots |
Check it yourself
- Download a version's manifest and its .ots proof.
- Drop both on opentimestamps.org, or run
ots verifywith the OpenTimestamps client, to see the Bitcoin block that proves when the manifest existed. - Each line of the manifest is one message's fingerprint. In Satoshi Mail, open a message's details and choose Verify this message to recompute it in your browser, or see tools/timestamp.py for exactly what is hashed.
The fingerprints prove the archive hasn't changed since it was timestamped. They don't prove who first wrote a message: for that, each message links to its original source.