2 ms·
How so? You don't reveal any coordinates if the foil covering the page is 3x the size of the page.
by amenghra 4y ago
How so? You don't reveal any coordinates if the foil covering the page is 3x the size of the page.
- moffkalast 4y agoWell whoever's doing the verifying would need to have a way to align that piece of foil in a way that shows the position, and unless both people know that process it's useless anyway. If there's infinite possible alignments then you've given no data, but a piece of foil with a random hole in it. Like giving you two random numbers and you coming up with a function that maps them to waldo's position.
- amenghra 4y agoYou might not have understood how this works. The prover shows the fact that they know Waldo's position by showing the page covered in foil to the verifier in person (or by taking a picture). The verifier does not manipulate anything. Obviously, there's no way to verify that the page under the foil is the page you think it is. This is more of an analogy / tool to explain things vs an actual secure protocol.
- moffkalast 4y agoThinking again, I may have read too much into the foil thing. A better example would be a just a cut-out of Waldo, separate from everything else. I'm sure it's a massive simplification of the way it's actually used.
- amenghra 4y agoTrue. Or a photocopy of the page + cut-out to make it non-destructive. Or just a picture of the page cropped around Waldo.
- Double_a_92 4y agoBut then what is the point of the foil? Just take a very zoomed in photo of Waldo?
- amenghra 4y agoRight, that would be equivalent. Or a regular photo which is then cropped.
- yencabulator 4y agoIt's a real-world application of cropping the visible area, for a kid to show to another kid, ELI5 style.