> generate collisions and as a minor point of clarification: The structure of the publish perceptual hash (and presumably the non-public one as well) were vul

> generate collisions and as a minor point of clarification: The structure of the publish perceptual hash (and presumably the non-public one as well) were vulnerable to essentially arbitrary second preimage attacks, not just collisions. This means that I can take an image and can usually adjust it to have an arbitrary hash, even a hash of an image I've never seen. It's much more powerful than a collision attack (where the attacker must modify both images). I doubt have any serious doubt that I would be unable to generate second preimages for two such hashes, but given the second hash was never published that just remains speculation. As AFAIK the first person to develop and demonstrate the second preimage attack against it, I'd like to think that my speculation on this is at least somewhat better than chance. :)