Document seal
“The founding-author call, narrated by the founder and published on the @HeartwoodLibrary YouTube channel. Any copy of the file verifies against this fingerprint, forever. The written call is sealed as block #28.”
Sealed document: founding-call-en.mp4 (the document itself is not published; its sha256 fingerprint below is what the author sealed).
Have the document? Choose it and the fingerprint is computed here in your browser; nothing is uploaded.
The proof bundle contains the sealed block, the author’s public key, and the exact recipes. The verifier is a single dependency-free script; read it before you run it.
Proof bundle (JSON)Independent verifier (node)Signed chain tipRaw chainOpen protocol spec
node verify-seal.js proof.json --document your-file
Place this next to the statement on any site; it links readers back to this certificate.
<a href="https://heartwoodlibrary.org/seal/9e99813b4386ffa28226d06e00b58333efc943b288fed97c59070f6797b99153"><img src="https://heartwoodlibrary.org/badge/9e99813b4386ffa28226d06e00b58333efc943b288fed97c59070f6797b99153.svg" alt="Sealed in Heartwood Library" width="252" height="36"></a>
The QR encodes this certificate’s address, so any phone camera becomes the verification entry point: print it on the cover page, the report footer, the poster. Scan, land here, check the copy. No app needed.