Certificate of authenticity · Verification code HB7G3Z3TQC · Version 1
Observattions from a hill - 1
Tim Berresheim
| Inventory number | TB06/E 15/7 |
|---|---|
| Year | 2006 |
| Technique | Risographie |
| Dimensions | 40 × 30 cm |
| Edition | 7/7 |
| Issued | 13.11.2026, 08:07 |
Timestamp anchored in Bitcoin, block 975648.
Verification
- …Checksum of the certificate file
- …Artist’s signature
- …Timestamp in Bitcoin
- ·ImageDrop the image file here to compare it with the certificate.
Drop a file here: image, certificate (.json), signature (.sig) or timestamp (.ots). Nothing is uploaded; everything is computed in your browser.
Verification data
- SHA-256 of the certificate file
5c278a36e90c0c472820b9864ed43282cd76ba7d78844cf9f68c463deb442ecb- Signature (Ed25519, Base64)
hDZPVupH4FsB3Zlwet+2gIfy6ta2EBjeYchIihX+/eb256x4R8ZJ33JqFjhEnxgspa/LMFNVxUSK+tAVDZqbAA==- Artist’s public key
0a347c3cdcf869a45213eb6eea4e65d4f60adb6d1fe7d9be59eace1f04584708- SHA-256 of the main image
fa07cf1c6602192f5e94b601073c9c83180d09486f3a0b41d57f29ce43cd882c
How to verify this independently of this page: hash the JSON file with SHA-256; the value must match the checksum above. Verify the signature against that checksum with the public key (Ed25519). Check the .ots file together with the JSON file at opentimestamps.org: this proves since when the checksum has been in the Bitcoin blockchain. The proof depends neither on this address nor on the artist, only on certificate, key and blockchain.