How to verify a work

Every original carries marks that do different jobs: a chip on the back, a record the artist signed, and a code written under the paint. No single one of them is the whole answer, and you do not need this website to check the most important of them.

Look up a work by its code

If you have the ten characters from under the paint, or from the work's label or certificate, type them here. Spaces and dashes do not matter.

The lookup tells you which work a code identifies and opens its page. It is not proof that the object in front of you is that work: the chip on the back is what answers that.

1. The chip on the back

A small disc on the reverse holds a secret key that was written into it once and can never be read out again. Hold a phone against it and it produces a code, a new one every time, that only that chip can make.

Tapping opens a page that says whether the code was genuine, and asks you to tap once more: the second tap confirms the chip itself is present. If the page says the code has been used before, you have most likely opened a saved or forwarded link rather than tapping the chip yourself. Tap it again.

2. The artist's signed record

When a work is finished, its details are written into a short document and signed with the artist's own hardware signing device. The document is then dated by independent timestamping services, so the date does not rest on the artist's word. It does not depend on this website: the signature and the dates can be checked in the document, for as long as it exists.

Checking it without this website

1. Find the signing address on the certificate or paperwork that came with the work.
2. Confirm that address against a source the seller does not control — this website, and at least one other channel of the artist's. Do this first. It is what connects the record to the artist, and it is the one step that does not rely on anything supplied with the work.
3. Check the signature. It is a standard Ethereum signed message over the record's fingerprint, so any tool that checks those will tell you which address made it. It should be the address you just confirmed.
4. Check the dates. They are standard RFC 3161 timestamps, which common tools such as OpenSSL can verify against each authority's published certificates.

If any of that is unfamiliar, get in touch and the artist will walk you through it.

For step 2, the signing address published here is 0x84908e29337cd6f4ea7660d82bf52204bfe0db50. Compare it with the artist's other channels rather than taking this page's word for it — that is the entire point of the step.

3. The mark under the paint

A ten-character code is written in ultraviolet ink beneath the paint film and is visible only under a UV torch. Its job is to survive: if the chip and the label are removed, the work can still be identified. Read it by eye and type it into the lookup above.

It is worth being precise about what this is not. The code is a reference to the work's record. It is a label, not a signature, and it is not by itself proof of who painted the picture.

If the check does not work

The tap and lookup pages need this website to be running. The artist's signed record does not. So if tapping the chip gives you an error, or nothing at all, that tells you something about the website and nothing whatever about the artwork. Check the record directly, as above, or get in touch.

What all this proves, and what it does not

Taken together, these show that the artist signed a document and a photograph at a particular time and linked them to this chip, and that the chip on this work is the one the artist fitted. That is the checkable claim.

No amount of cryptography can look at a canvas. Judging the physical object is still a matter for your own eyes, the artist's photograph, and — if the value warrants it: a conservator.