Verify Authenticity

Every sold work is accompanied by a certificate. It carries a QR code, and this code can prove two things: that the certificate actually comes from the artist, and that it belongs to this exact image.

How it works

First, scan the QR code on the certificate. Second, photograph the artwork under normal light, filling the frame as much as possible and from as straight in front as possible. The result appears immediately.

What is checked

The QR code contains the information about the work, a feature computed from the image and a digital signature. The signature is checked against the artist's publicly stored key: it cannot be created without his private key and would become invalid after any later change to the certificate.

The same feature is then computed from your photograph and compared with the one stored in the certificate. Because no photograph is ever exactly the same twice, this comparison uses a tolerance range. It was measured on the works themselves: different brightness, different artificial or daylight conditions and capture with a phone camera change the feature only slightly, while different works differ clearly.

Your photograph does not leave your device

The entire check takes place in your browser. Neither the QR code nor the photograph is transmitted or stored. No log is created of who checked which work.

What the procedure shows, and what it does not

It proves that a certificate is genuine and unchanged and that it belongs to the picture in front of you. It does not replace art-historical assessment and cannot rule out a very careful handmade copy. For that purpose there is provenance and, if necessary, examination of the original.