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Re:Hash collision in Apple NeuralHash model by UncleMeat on Wednesday August 18, 2021 @07:52AM (#28219949)
Why is this meaningfully different than, say, what Google Photos has been doing for years?

If you can get rooting malware on the target device then you could

1. Produce actual CSAM rather than a hash collision

2. Produce lots of it

3. Sync it with Google Photos

This attack has been available for many years and does not need convoluted steps like hash collisions if you have the means to control somebody's phone with a RAT.

Re:Hash collision in Apple NeuralHash model by UseStrict on Wednesday August 18, 2021 @09:56AM (#28220965)
The _initial_ implementation of client-side scanning has the same initial result, but vastly different futures. Up until now it could be (foolishly or otherwise) assumed that Apple had your personal privacy in mind. Now they have demonstrated a willingness to compromise your local device privacy. Right now it's iCloud only, but I'm sure it's a boolean configuration away somewhere to make it scan everything, regardless of whether it's marked for iCloud upload or not. And I don't think Apple is strong enough to withstand a gagged demand to flip that boolean.

On their cloud services (Apple, Google, MS, etc) they can only get to content that a user has implicitly agreed to share (whether or not they understand the ramifications is another conversation). On your device, there's no more separation.

Re:Hash collision in Apple NeuralHash model by UncleMeat on Wednesday August 18, 2021 @10:33AM (#28221481)
But the discussion here is about malicious actors fraudulently inserting files that trigger alarms. If they have control over your device, "content that a user has implicitly agreed to share" is not a meaningful category.
Re:Hash collision in Apple NeuralHash model by cyanite on Wednesday August 18, 2021 @04:23PM (#28226597)
How have they demonstrated that they will compromise your privacy? They compromise it less than the systems scanning on the cloud, since like this most of the match is only known to the device and not the cloud.

If you don’t trust Apple to not lie, then the entire discussion becomes a bit moot, I think, since then they could pretty much do anything, with or without this system.

Re:Hash collision in Apple NeuralHash model by grishka on Wednesday August 18, 2021 @10:17AM (#28221227)
The big difference is that cloud providers do the scanning on their own infrastructure. If you don't want something scanned, you don't upload it to the could, that simple. But here, your own device is snitching on you.
Re:Hash collision in Apple NeuralHash model by UncleMeat on Wednesday August 18, 2021 @10:35AM (#28221510)
But the discussion at hand is about malicious actors causing innocent people to trip the alarms. Given the clear capabilities of tools like Pegasus, "just don't enable cloud syncing" is obviously not sufficient to protect against a malicious actor who wants to plant illegal content on your device and trip the alarms.
Re:Hash collision in Apple NeuralHash model by hannasanarion on Wednesday August 18, 2021 @03:02PM (#28225710)
OK, and so what? "Tripping the alarms" in this case means somebody looks at the pictures that were put on your device without your knowledge, sees that they're all grey blobs, and flags it as a false alarm, case closed.
Re:Hash collision in Apple NeuralHash model by cyanite on Wednesday August 18, 2021 @04:24PM (#28226603)
No. Only pictures being uploaded to iCloud Photo Library are being scanned.
Re:Hash collision in Apple NeuralHash model by short_sells_poo on Wednesday August 18, 2021 @08:08AM (#28220053)
Google was not standing on a pedestal preaching privacy. In contrast Apple was trying to appear as the privacy conscious hardware/software vendor. To now implement such a blatantly obvious stepping stone to dragnet surveillance of actual devices is such a hypocritical move that it beggars belief.

Ignoring the whataboutism in your question, we know that privacy once lost is practically impossible to get back. Once the genie is out of the bottle and Apple is doing on device scanning, what's to stop 3 letter agencies and governments around the world to start demanding ever more access? Because that's exactly what's going to happen. "Oh it's not a big deal, we just need slightly more access than we have now."

10 years down the line, we'd have people's phones datamining every piece of info they have and silently reporting to an unknowable set of entities. All in the name of fighting crime.

There needs to be pushback on this crap. Every single one of these attempts must be met with absolute and unconditional refusal. Mere inaction means things will inevitably and invariably get worse over time.

Re:Hash collision in Apple NeuralHash model by UncleMeat on Wednesday August 18, 2021 @08:41AM (#28220257)
It just seems to me that there are two very different conversations happening at the same time, with people swapping back and forth between them

1. There can be false positives or other mechanisms for innocent people to get flagged.

2. It is bad to do this sort of check on the local disk.

The discussion at hand started as entirely #1. But now you've swapped to #2, talking about government spying on local files. It makes it very difficult to have a conversation because any pushback against arguments made for one point is assumed to be pushback against arguments made for the other point.

Re:Hash collision in Apple NeuralHash model by stetrain on Wednesday August 18, 2021 @09:52AM (#28220921)
This exactly.

I am mostly convinced based on the technical details that have (slowly) come out from Apple that they have made this system sufficiently inconvenient to use as a direct surveillance system by a malicious government.

Yes a government could secretly order Apple to make changes to the system, but they could also order them to just give them all of your iCloud photos and backups, or send data directly from the Camera or Messages app, or any number of things that would be easier and more useful for the government. If you don't trust your government don't use a mobile device on a public cell network or store your data on servers.

But all of that said there is a still a line being crossed on principle and precedent for scanning images locally on device and then reporting out when something "bad" is found.

Apple thinks this is more private than just directly rifling through your photos in iCloud, but I can draw a line between what is on my device and what I send to Apple's servers and be comfortable with that.

Re:Hash collision in Apple NeuralHash model by short_sells_poo on Wednesday August 18, 2021 @10:40AM (#28221587)
Yes of course it is more private than outright scanning all photos but how does that relate to the ground state of private photos simply not being scanned at all?

And please do not bring in whataboutist arguments like "but other cloud providers are already doing it".

I'm honestly taken aback by how many people on HN are completely OK with what Apple is pulling here.

In my mind, it's irrelevant that the current system is "sufficiently inconvenient to use as a dragnet surveillance system", because it's the first step towards one that is convenient to use and if we extrapolate all the other similar efforts, we know full well what is going to happen.

Re:Hash collision in Apple NeuralHash model by stetrain on Wednesday August 18, 2021 @10:46AM (#28221692)
I don't think "All user data on device and in the cloud is not scannable for CSAM or retrievable with a warrant" is a tenable position in the current US political landscape, and even less so in other countries.

And my point is that if the government wanted a dragnet they could just legislate or secretly order one. Just like they have done in various forms over the last 20 years. And Apple might not even be allowed to tell us it is happening.

Re:Hash collision in Apple NeuralHash model by short_sells_poo on Wednesday August 18, 2021 @11:22AM (#28222431)
> "All user data on device and in the cloud is not scannable for CSAM or retrievable with a warrant" Who said anything about warrants? As far as I know the proposed system is proactive and requires no warrants at all.

More to the point, anyone remotely sophisticated can just encrypt CSAM into a binary blob and plaster it all over the cloud providers servers.

Ie, this system will possibly catch some small time perverts at the cost of even more potential of government misuse of the current technical landscape.

I consider it a similar situation to governments trying to legislate backdoors into encryption. A remotely sophisticated baddie will just ignore the laws, and all it does is add risks for innocents.

> And my point is that if the government wanted a dragnet they could just legislate or secretly order one. Just like they have done in various forms over the last 20 years. And Apple might not even be allowed to tell us it is happening.

I don't understand how is this an argument against the pushback at all. So just because it could be worse, we should just throw our hands in the air and say "Oh it's all fine, it could be worse so the (so far) mild intrusion into privacy is nothing to worry about."

The thing is, these things seem to happen step by step so the outrage is minimized. Insert your favorite "frog being boiled slowly" anecdote here. You don't push back on the mild stuff, and before you realize things have gotten so much worse.

Re:Hash collision in Apple NeuralHash model by stetrain on Wednesday August 18, 2021 @11:36AM (#28222712)
I haven’t ever said this is a good thing and that we should like it.

I’m saying if the concern is that a government orders Apple to change it and do something different, then that’s a government problem and maybe we should try fixing that.

Re:Hash collision in Apple NeuralHash model by short_sells_poo on Wednesday August 18, 2021 @12:15PM (#28223382)
> then that’s a government problem and maybe we should try fixing that.

But why even give governments hints that people are generally OK with their devices being scanned?

We can argue about the technicalities of how abusable or resilient the current implementation is. But we can agree that it's a step towards losing privacy, yes? We didn't have scanning of iDevices before, now we do.

Because in my mind it's not a long shot to argue that once it becomes normalized that Apple can scan people's phones for CSAM when uploading to iCloud, it's just a small extra step to scan all pictures. The capability is basically in place already, it's literally removing a filter.

And then the next small step is not just CSAM but any fingerprint submitted by LE. And so it goes.

Governments can't legally compel Apple to implement this capability. But if the capability is already there, Apple can be compelled to turn over the information collected. Again, they can't do that if the capability and information doesn't exist.

E.g. if Apple can't decrypt data on your phone because they designed it such, then they can't be forced, even with a warrant, to backdoor your phone. They can legally refuse to add such capabilities.

Re:Hash collision in Apple NeuralHash model by stetrain on Wednesday August 18, 2021 @12:55PM (#28223960)
> We can argue about the technicalities of how abusable or resilient the current implementation is. But we can agree that it's a step towards losing privacy, yes? We didn't have scanning of iDevices before, now we do.

Yes, that was the intention of my original comment. The “slippery slope” is one of principle and precedent, more than this specific technical implementation.

Re:Hash collision in Apple NeuralHash model by short_sells_poo on Wednesday August 18, 2021 @10:35AM (#28221518)
I'd argue they are both important points that are tightly interconnected.

#2 is bad on it's own and in my mind it shouldn't even get to the merits of discussing #1 because at that point the debate is already lost in favor of surveillance.

But beyond that, #1 is highly problematic, doubly so given the fact that government surveillance is basically a non-decreasing function.

Re:Hash collision in Apple NeuralHash model by cyanite on Wednesday August 18, 2021 @04:26PM (#28226629)
I’d argue that #2 is good, since it offers much more privacy than scanning in the cloud. This is based on reading and understanding the technical summary and paper linked from there.
Re:Hash collision in Apple NeuralHash model by dang on Wednesday August 18, 2021 @02:48PM (#28225526)
(We detached this subthread from https://news.ycombinator.com/item?id=28219296.)