Certificate of authenticity · Verification code DNW5K78WYM · Version 1

HERE AND NOW VI

Tim Berresheim

HERE AND NOW VI
Inventory numberTB09/F 115
Year2009
TechniqueFace-Mount Archival Pigment Print hinter Acrylglas, rückseitig auf Aluminium kaschiert, gerahmt.
Dimensions150 × 100 cm
Editionunique
Issued13.11.2026, 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
29225e4ebd3515939bbb86caf048fa60fe0909ccc7f4d727cc02fdd9386d1a81
Signature (Ed25519, Base64)
XVDJnSVXrsIqeA+xw0n3sK/mGjJdLw1riQvWqz7yvRF4JvJlkpoIazGHtiH2hhYQypa4VcV4a/Z0q5KUeePwDA==
Artist’s public key
0a347c3cdcf869a45213eb6eea4e65d4f60adb6d1fe7d9be59eace1f04584708
SHA-256 of the main image
f840518da5b57c9a27fb3f99b28af98103c61d4e4b4d8305259ded148a4fdfa8

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.

↑