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Apple CSAM Detection – Technical Summary [pdf]

by rantwasp on 8/6/21, 5:32 AM with 3 comments

  • by rantwasp on 8/6/21, 5:38 AM

    The Big Brain Scheme Apple uses for their CSAM stuff.

    Summary for the lazy: - this is going to be out in ios15

    - Apple will build and push a database of hashes with every update

    - these hashes will be used to verify against the pics before they are uploaded to icloud and generate a "voucher"

    - once a certain threshold of vouchers is passed, Apple will be able to decrypt the pictures in questions (all this discussion seems to assume Apple does not have access to icloud pictures - so maybe they are preparing to rollout full encrypted backups???)

    - the crypto stuff is interesting

    - the scary part is that there is nothing preventing Apple to do the same thing with other thing on your phone (assuming there is a way to generate a good enough matching hash - I can see how this could be easily extended to basically anything that's stored on the phone)