Apple CSAM Detection – Technical Summary [pdf]
apple.com
apple.com
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)
They may have been secretly doing this all the time. I don’t see them being open about this changing that.
In the end, it’s all about whether you trust them. If you don’t, either don’t buy an iPhone, or wait until people you do trust have reverse engineered its software so far that you can trust the OS.
also this applies to new pictures (not what you already have)
again, if you believe what they are sharing