ThreatExchange VS vpv

It’s somewhere in the FAQ at https://stopncii.org/faq/, but It’s PDQ for photos (https://github.com/facebook/ThreatExchange/tree/main/pdq) and MD5 for videos. PDQ is resistant to some modifications (it focuses on the ones that come from regular usage, such as changing the format from gif to jpg, or a filter changing colors or brightness), but it’s not as resistant to modifications as you could get by training dedicated classifiers or other approaches that you might do with the original media or by storing more context, which StopNCII chose not to do.

The FAQ (https://stopncii.org/faq/) mentions its using PDQ (https://github.com/facebook/ThreatExchange/tree/main/pdq) for images, and MD5 for videos. Companies would then use hashes to scan their platform.

Meta also has a post on it: https://about.fb.com/news/2021/12/strengthening-efforts-agai...

Notably, none of the the algorithms tested in the cited study are Apple's NeuralHash, or comparable algorithms. They look at aHash, pHash (plus a variant thereof), dHash, and and PDQ (used at Facebook for similar applications, apparently). The first 4 data to between 2004 and 2010; the last is more recent, but conceptually similar - the citation [0] for PDQ puts it in the same bucket of 'shallower, stricter, cheaper, faster' algorithms as the first four.

No one has proposed any of those as 'illegal image detectors'. Apple's NeuralHash may or may not be robust to the same or different perturbations but the cited study provides basically no new information to inform the conversation its press release wants to be a part of.

[0]: https://github.com/facebook/ThreatExchange/blob/main/hashing...

Check out vpv: https://github.com/kidanger/vpv Also, here is a good list of various apps, in case you need something else: https://wiki.archlinux.org/index.php/List_of_applications