4 ms·

Yes, the observer (preferably multiple) is an integral part of the process. The second signing is an interesting idea, though I'm not sure if it would prove mor

• kazinator 5y ago
  "verifying the code" means absolutely nothing. Any code you're verifying is from the past, and could be edited into any image from any time in the past. All you know is that neither the image nor the code came from the future, which is self-evident. I suspect the idea here is to rely on it being difficult to forge a printed version of the QR code that is shot together with the scene. For that purpose, a newspaper is better; it is more complex. I mean, someone could take a picture in, say, the year 2032, using a new QR code (printed on paper and everything), and then carefully edit an old QR 2022 QR code into that image. It's a very regular, high contrast, simple image. In the era of deep fakes, I can't believe someone would think any of this is "beyond the shadow of a doubt".
  • miunau 5y ago
    A newspaper might not be available; often pictures with a blank piece of paper with the date written are used. QR Date relies on the signature in the QR code, not just the date, which makes it harder to fake within a reasonable amount of time. The proof is based on the public key being from a trusted authority, and the speed of dissemination. I don't think anyone has said "beyond the shadow of a doubt" besides you. Reasonable doubt is a different thing. If you wanted more veracity, you could always keep on taking more pictures around the subject with more codes, or just keep holding the generator within frame for video.