Certificate of authenticity · Verification code 4X6M6L27M5 · Version 1
Übung im Lauern IV
Tim Berresheim

| Inventory number | TB17/P 111/1 |
|---|---|
| Year | 2017 |
| Technique | Harz und Pigmente auf Papier |
| Dimensions | 50 × 45 cm |
| Edition | 1/3 |
| Issued | 13.11.2026, 08:06 |
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
6192cee5de19dbed0ee59a86adbc213317f78f5a4a014039868e3a8cbaad167f- Signature (Ed25519, Base64)
OWdP8kGGLEmW4NP80F/Oe20y5xKbhq2Qu4giFj9UV52+V/p/PCYfL4IAuTkSXSej+AKAEgwHaKe+VmaK/j5WDg==- Artist’s public key
0a347c3cdcf869a45213eb6eea4e65d4f60adb6d1fe7d9be59eace1f04584708- SHA-256 of the main image
60f82bd7b9daea4d5290490ebb1aee7358580462ef7d3376bfa22fb972560847
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.