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Comment by PaulDavisThe1st | Hacker News Reader

> Apple generates the on-device perceptual CSAM hash database through an intersection of hashes provided by at least two child safety organizations operating in separate sovereign jurisdictions – that is, not under the control of the same government. Any perceptual hashes appearing in only one participating child safety organization’s database, or only in databases from multiple agencies in a single sovereign jurisdiction, are discarded by this process, and not included in the encrypted CSAM database that Apple includes in the operating system.

Well, that's quite clever, isn't it.

It's just the sort of thing that someone who had "never heard of" the Five Eyes, or extradition treaties or illegal rendition operations involving multiple nations, might come up with.

Genius!

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well crap I just wrote a response lecturing you on the Five Eyes collusion before reading the last two lines of your post. :P

There exists a kind of sufficiently advanced stupidity that it can only be constructed by really smart people. People who are smart enough to rationalize doing something which is transparently wrong.

Curious, does any technological system used widely, standup to the threat levels you mentioned?

Probably not.

Does any technological system used widely justify itself by saying "it would take two national jurisdictions cooperating to break this?"

Was not defending this measure, my question was out of curiosity

China: here’s our database and here is one for Hong Kong.

They’re totally separate we promise.

Separate but identical, indeed.

If your threat model includes pervasive spying by multiple nation states, and being grabbed in the night by black helicopters, it seems unlikely you'll be overly concerned about them precisely inserting at least 30 of your photos into multiple CSAM databases and also co-ercing Apple's manual review to get you reported to NCMEC.

I don't think people are worried about multiple nation states framing them with CSAM photos - they're worried about multiple nation states in an intelligence collaboration poisoning both sets of hash lists with non-CSAM material, so that there is an intersection that makes it onto the device.

There is still that Apple human reviewer once the threshold has passed. What I would love to ask Apple is - what happens if/when their reviewers start noticing political material, religious material, etc. is being flagged on a consistent basis, thereby insinuating that the hash list has been poisoned. What's their play at that point?

The document states that incorrectly flagged items are forwarded to engineering for analysis. Given their target false-positive rate (1 in 3 trillion, was it?) it seems likely that engineering would very carefully analyze a rush of false positives.

I think you have this backwards.

Given that nations already "grabbing in the night with black helicopters" (semantically, at least), and do so with impunity, it doesn't seem much of a stretch to imagine they'd potentially set someone up using this much milder sort of approach.

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