You missed the widely panned Apple iCloud child sexual abuse imagery detection feature. The private set intersection is basically doing homomorphic encryption.

You missed the widely panned Apple iCloud child sexual abuse imagery detection feature. The private set intersection is basically doing homomorphic encryption. In raising some very valid policy critiques, people forget that it's actually a nifty piece of engineering. (This is not an endorsement of that feature.) https://www.apple.com/child-safety/pdf/Apple_PSI_System_Security_Protocol_and_Analysis.pdf https://www.apple.com/child-safety/pdf/Apple_PSI_System_Secu... I'm also closely working together with a team at $WORK who's using a protocol very similar to Apple's but not doing CSAM detection. We are seeing some severe pushback on this technology. I wouldn't be surprised if there are multiple homomorohic encryption based products at Big Tech that have yet to see the light of day.