It would be trivial to have the same payload on each device, and extract different answers using the matching server side db which varies by country.
Perhaps not trivial, but just short.
I honestly don't think Apple wants to deal with any of that crap and that they would rather silently can the system and do exactly what everybody else does than place themselves in the line of fire when their own unique trademark system is being abused.
Suffice to say, unless you provide proof, I am reasonably confident there’s no way to verify the hash db doesn’t contain extra hashes other than the CSAM hashes provided by the US government. But I’ve been wrong many times before.
If what you mean by blinded is that you don't know what the source image is for the hash, that's true. Otherwise Apple would just be putting a database of child porn on everyone's phones. You gotta find some kind of balance here.
What do you mean you can't verify it doesn't contain extra hashes? Meaning that Apple will say here are the hashes in your phone, but secretly will have extra hashes they're not telling you about? Not only is this the kind of thing that security researchers will quickly find, you're assuming a very sinister set of features from Apple that they'll only tell you half the story. If that were the case, then why offer the hashes at all? It's an extremely cynical take.
The reality is all of the complaints about this system went from this specific implementation, and then as details get revealed, it's now all about the future hypothetical situations. I'm personally concerned about future regulations, but those regulations could/would exist independently of this specific system. Further, Dropbox, Facebook, Microsoft, Google, etc all have user data unencrypted on their servers and are also just as vulnerable to said legislation. If the argument is this is searching your device, well the current implementation is its only searching what would be uploaded to a server instead. If you suggest that could change to anything on your device due to legislation, wouldn't that happen anyway? And then what is Google going to do... not follow the same laws? Both companies would have to implement new architectures and systems for complying.
I'm generally concerned about the future of privacy, but I think people (including myself initially) have gone too far in losing their minds.
At no point is anyone besides Apple able to view any NeuralHash hashes from the CSAM database. You can verify the database is the same on all iPhones, but you are not able to look at any of the hashes.
Is the issue that you want to take a given photo that you believe the CCP or whomever is scanning for, compute a NeuralHash, and then see if that's in the db? Or are you wanting to see if your db is different from other phone's db's? Because I think the later is the one that most people are concerned about.
On the flip side, though, at least Apple will have given us a canary. And that's why I don't think Apple will be asked to add these hashes: if the governments don't want their citizens to know what's being scanned server side, pushing the equivalent data to clients would tip their hand. They might just write Apple off as a loss and rely on Google, Facebook, etc.