Document seal

Demo video: Seal a document

by Stefania Overman ✓ signed with granted key 3391cebb120892c6sealed 2026-09-07block #22

“Official Heartwood Library demonstration video, published on the @HeartwoodLibrary YouTube channel. Any copy of the file can be verified against this fingerprint, forever.”

Sealed document: demo3-seal-a-document.mp4 (the document itself is not published; its sha256 fingerprint below is what the author sealed).

seal id: 1e5ce8b7ba29ce9c31d6e600f32b36f5983e6a8d0930ff107ea5883b4613f094

statement sha256: ef4ff2ccf8d6e29fb2141ea10eb4fd56021e173c0dce506702400f30a0d17ec4

document sha256: ddf99b1b33aa0fafd940d65c5e7155cc70a8bab374fb338da9e669cd23b08828

signing key: 3391cebb120892c6 (Ed25519, granted on chain in block #8)

Check your copy

Have the document? Choose it and the fingerprint is computed here in your browser; nothing is uploaded.

Verify without trusting this server

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 tip Raw chain Open protocol spec

node verify-seal.js proof.json --document your-file

Embed the badge

Place this next to the statement on any site; it links readers back to this certificate.

<a href="https://heartwoodlibrary.org/seal/1e5ce8b7ba29ce9c31d6e600f32b36f5983e6a8d0930ff107ea5883b4613f094"><img src="https://heartwoodlibrary.org/badge/1e5ce8b7ba29ce9c31d6e600f32b36f5983e6a8d0930ff107ea5883b4613f094.svg" alt="Sealed in Heartwood Library" width="252" height="36"></a>

Print the QR on the document

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.