Hacker News Reader

https://hackerfactor.com/blog/index.php?/archives/931-PhotoD... is linked from https://anishathalye.com/inverting-photodna/ and is likely a good starting point

thanks!

Yeah Hacker Factor's multi-post critiques are where I first saw it analyzed. For reference they run the popular fotoforensics.com image analysis site.

They also have scathing critique (eg [1]) about the Adobe-led C2PA digital provenance signing, having themselves been part of various groups that seek solutions to the provenance problem.

[1] https://www.hackerfactor.com/blog/index.php?/archives/1013-C...

There tends to be more information under the search term "perceptual hashing"

The secrecy of the inner tech is intentional.