Verify a seal·Worked example
Every claim we make, anyone can verify.
Each artefact our engine emits — every sealed brief, every receipt — is independently time-stamped to Bitcoin via the OpenTimeStamps protocol and signed with Aeterna's sovereign architect key. The proof lives on a public blockchain. Years later, anyone can verify it.
253,460+ artefacts anchored to date · zero retroactive edits possible
One example · pulled live from our archive
Anchored
Seal 00005cd988cd…92aefd714654
Fingerprint
00005cd988cd45c035c78e5d030e381372826f758907efca7aef92aefd714654
Cryptographic fingerprint of the sealed artefact. Recomputable byte-for-byte; cannot be silently altered.
Submitted
2026-05-21 13:02:57 UTC
Hash submitted to three independent OpenTimeStamps calendar servers.
- ·alice.btc.calendar.opentimestamps.org
- ·bob.btc.calendar.opentimestamps.org
- ·finney.calendar.eternitywall.com
Bitcoin block
Anchored 2026-05-21 13:51:26 UTC · 48 min after submission.
Authority timestamp
Confirmed by freeTSA — a public RFC 3161 time-stamping authority.
Belt-and-braces: independent of the OpenTimeStamps calendars and of Bitcoin itself.
·What this means
The brief you receive carries the same proof.
Every sealed brief minted in a Sit-Down lands in your inbox with the same shape as the example above: a cryptographic fingerprint, a sovereign signature, and an independent Bitcoin time-stamp.
If we ever change a word, the fingerprint changes. If the fingerprint changes, the Bitcoin anchor stops verifying. Either we delivered exactly what was sealed, or you know we didn't — there is no in-between.
That is the only kind of promise worth making.
The infrastructure
Built in-house. Operated by Aeterna Systems. Verifiable by anyone, anywhere, offline.