> Given that changing one pixel of an image changes its hash They don't use SHA/MD5 style hashes for CSAM image matching; they use "perceptual hashes"[1] which

> Given that changing one pixel of an image changes its hash They don't use SHA/MD5 style hashes for CSAM image matching; they use "perceptual hashes"[1] which are resilient to changes (specifically, I believe, PhotoDNA[2] from Microsoft.) [1] https://en.wikipedia.org/wiki/Perceptual_hashing https://en.wikipedia.org/wiki/Perceptual_hashing [2] https://www.microsoft.com/en-us/photodna https://www.microsoft.com/en-us/photodna