Certificate of authenticity · Verification code H3658YPS3Z · Version 1
RGB (QUESTIONMARK) FOTO I
Tim Berresheim
| Inventory number | TB08/F 491 |
|---|---|
| Year | 2008 |
| Technique | C Print (Chromogendruck) |
| Dimensions | 235 × 180 cm |
| Edition | AP II |
| 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
149edfcf157e1b94d37301d3d87eea2b0bd1bcfc2e5314664581a029ad8a3cb1- Signature (Ed25519, Base64)
vVwtR6UpzjDFbfcyMlM/K+2tcMYyS0nS9F7ENJ/1buSf12W9awi+3If9XoeixgFANNdIvkZ62A2e7LArtopUCA==- Artist’s public key
0a347c3cdcf869a45213eb6eea4e65d4f60adb6d1fe7d9be59eace1f04584708- SHA-256 of the main image
f16014036c6dc9cca9ee7a68725dd705b33bd6790ee5fe1c37c694bbb7adf5ac
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.