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Apple plans to scan US iPhones for child abuse imagery

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Re: Apple plans to scan US iPhones for child abuse imagery

#381

Earlier quoted context omitted.

I don't disagree there, I'm just pointing out that there is a difference between the two cases.

Your argument was wrong, though, because those vaccines aren't being given to children anyway.

Reading back now, I realize my comment was indeed just dumb and borne from not properly reading the OP's comment and thinking of the anti-vaxxer movement in general, not the actually rational aversion to untested ones during the Covid crisis.

I would have editing a disclaimer on it but it's too late.

Re: Apple plans to scan US iPhones for child abuse imagery

#382

Earlier quoted context omitted.

Who would add “gray area” pictures to the database of CP images that are matched?

Material that is deemed illegal in jurisdiction A but not in B. Material for which someone was once convicted but if found on someone else's device would not be illegal. Material isn't added to these databases after sober legal deliberation. Police agencies can add basically anything they see fit.

This is a system for just one jurisdiction though? Is there talk about doing this outside the US? For multiple jurisdictions you’d need different sets of known hashes.

Re: Apple plans to scan US iPhones for child abuse imagery

#383
post #329
post #287

Earlier quoted context omitted.

US has a high crime rate, because it has laws introduced specifically to increase the crime rate in specific racial groups; that’s where the War on Drugs came from. China doesn’t count Uyghur extremists as incarcerated for the same reason the US doesn’t count their brethren it kills en masse in Middle East as death sentences. It’s just a different thing. As for the rest of the list - most of it is just US state propa…

> US has a high crime rate, because it has laws introduced specifically to increase the crime rate in specific racial groups; that’s where the War on Drugs came from. That's not true. If you released everyone convicted of a drug crime (including manufacturing, selling, or distributing), you'd decrease the US prison population by 20%.[1] I'm all in favor of ending the drug war, but that won't do much to the incarcerat…

Sentencing for drug possession has secondary effects - it pushes large number of people into other kinds of crime. Thus, you cannot count only the direct 20%.

Regarding other countries - what would happen (and happened) to countries that refused to join War on Drugs?

Regarding possession - in UK essentially nobody cares, unless you’re distributing industrial quantities and/or are really obnoxious about it, eg walk into Constabulary smoking a joint, or by putting up advertisements. There are regular news about eg police finding a suspect car parked for six hours with engine on, filled with smoke (actual example I remembered because it’s funny) and they don’t result in charges. I suppose the law could be used if you also committed other offenses.

As for not being able to talk politics in China: where all the policy and law changes come from then? And if you can freely talk in the US, why so many people have many throwaway accounts here on HN?

Anyway: yes, China is oppressive in a number of ways. It’s about one generation behind the US, except for racism, where it’s ahead. US itself is perhaps a generation behind Western Europe. But everyone knows what’s bad about China, and everyone knows what’s good in the US. Anti-Chinese propaganda is everywhere, and I find it quite annoying. Particularly so because it detracts attention from real problems - if American propaganda is lying about genocides and missile silos, why assume other parts are true? Secondary: all the bad stuff in China stays in China. They don’t routinely exterminate hundreds of thousands people in other countries for financial or racial reasons. They don’t intentionally ruin other nations’ economy. The US does. And I feel like this perspective is entirely lost among western population.

Re: Apple plans to scan US iPhones for child abuse imagery

#384
post #280

Earlier quoted context omitted.

Ok. Hashed-based image rec. Where are the hashes? Is the comparison done in my phone against a downloaded database, or is a hash of every image on my phone uploaded for comparison on a server? Could this program then be expanded to other classes of images? Animal abuse imagery? Terrorism? Hashes of known bomb-making instructions? How about people sharing illegal pdfs and text files? Will the MPAA be allowed to submit…

It’s done on Apple’s servers using your iCloud backups. For good or ill this lets people opt out by disabling iCloud. I would hope most privacy conscious people disable iCloud, but that’s another story.

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Re: Apple plans to scan US iPhones for child abuse imagery

#385
post #364

Earlier quoted context omitted.

Most of the process is done on customer's devices.[1] [1] https://www.apple.com/child-safety/pdf/CSAM_Detection_Techni...

I was answering this: “Is the comparison done in my phone against a downloaded database, or is a hash of every image on my phone uploaded for comparison on a server?” To be clear each image, the image’s NeuralHash, and a visual derivative are uploaded to iPhoto. This allows for the inspection of the NeuralHash algorithm used which I actually prefer. The phone isn’t downloading the hash database.

From that same page: "Apple further transforms this database into an unreadable set of hashes that is securely stored on users’ devices". The phone is downloading the hash database.

Re: Apple plans to scan US iPhones for child abuse imagery

#386

Earlier quoted context omitted.

> "The odds of This number is equivalent to generating 1 billion UUIDs per second for about 85 years." If we're talking about random files, sure. What if the files are intentionally created to match the desired hash? The malicious actor doing this could be a private party intending to disrupt your life, but it could also be law enforcement as a means of gaining access to your device when it would otherwise require a…

> What if the files are intentionally created to match the desired hash? That's called a second-preimage attack and is similarly infeasible to achieve against a cryptographically secure hash function. There are good arguments to be made for why this is a bad idea, but hash collisions aren't one of them.

But this isn't your average hash function.

This is a function that is created to be robust against modifications to the image.

A perfectly robust function would - in my opinion - be one that could detect even a recreation of the original setup.

I don't know where on this scale the function law enforcement use is, but if it is any good I struggle to see how it cannot detect similar legal imagesm

Re: Apple plans to scan US iPhones for child abuse imagery

#388
post #342

Earlier quoted context omitted.

Zero AI involved? Simple hashes? Source needed. From what I read, you are making false claims.

The PhotoDNA platform doesn’t offer the participating organization raw photos, just hashes. The AI part is stitching photos with matching edges together, incase someone cropped them into different parts. Again, Apple nor any company, have access to the source data, just hashes.

My point was that it can’t be “simple” hashes, as that is easy to defeat. I never said anything about Apple having the source images.

Re: Apple plans to scan US iPhones for child abuse imagery

#389
To everyone here who wishes we do nothing about this: you should rethink your position. There is a difference between “let’s be careful and design the right solution” and “let’s do nothing to maximize individual liberty”.

In 2017 a 369% increase in CSAM in terms of reports happened. The only explanation is that platforms now facilitate the sharing and a growing problem continues to grow.

In raw percentages the data clear: too many children are being abused and the numbers are growing.

https://storage.googleapis.com/pub-tools-public-publication-...

Re: Apple plans to scan US iPhones for child abuse imagery

#390

Earlier quoted context omitted.

> And now they will evolve by developing a simple system to modify pixels in images when they copy and transmit that will easily defeat this hashing system They don't use simple file hashes to match images, but perceptual hashes. That way they can find modified derivatives of a source image. The problem with this approach, though, is that this is ripe for false positives. Two completely unrelated images can have simi…

could you use multiple perceptual hash functions with different salts, so that collisions would be less likely while allowing derivatives to be detected?

That reduces to just inventing a “fancier” single hash function. This adds no value or security in cryptography; it just makes things slower. I expect the same is true of perceptual hashes.
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