4 ms·

Regarding false positives re:Apple, the Ars Technica article claims > Apple offers technical details, claims 1-in-1 trillion chance of false positives. There

Regarding false positives re:Apple, the Ars Technica article claims > Apple offers technical details, claims 1-in-1 trillion chance of false positives. There are two ways to read this, but I'm assuming it means, for each scan, there is a 1-in-1 trillion chance of a false positive. Apple has over 1 billion devices. Assuming ten scans per device per day, you would reach one trillion scans in ~100 days. Okay, but not all the devices will be on the latest iOS, not all are active, etc, etc. But this is all under the assumption those numbers are accurate. I imagine reality will be much worse. And I don't think the police will be very understanding. Maybe you will get off, but you'll be in a huge debt from your legal defense. Or maybe, you'll be in jail, because the police threw the book at you.

KarlKemp 5y ago
Do you really believe that if they scan your photo library at 10am and don't get any false positives, another scan five hours later, with no changes to the library, has the same chance of getting false positives as the first one, independent of that result?
- burnished 5y ago
  If you take photos, then yes?
- NoNotTheDuo 5y ago
  Even if the library doesn’t change, doesn’t the possibility of the list of “bad” hashes changing exist? I.e., in your example, a new hash is added to by Apple to the list at 11:30am, and then checked against your unchanged library.
  - IfOnlyYouKnew 5y ago
    Oh god have mercy on whatever has happened to these people…
nanidin 5y ago
> Apple has over 1 billion devices. Assuming ten scans per device per day, you would reach one trillion scans in ~100 days. People like to complain about the energy wasted mining cryptocurrencies - I wonder how this works out in terms of energy waste? How many people will be caught and arrested by this? Hundreds or thousands? Does it make economic sense for the rest of us to pay an electric tax in the name of scanning other people's phones for this? Can we claim it as a deductible against other taxes?
- FabHK 5y ago
  > I wonder how this works out in terms of energy waste? Cryptocurrency waste is vastly greater. It doesn't compare at all. Crypto wastes as much electricity as a whole country. This will lead to a few more people being employed by Apple to verify flagged images, that's it.
  - nanidin 5y ago
    In net terms, you're probably right. But at least the energy used for cryptocurrency is being used toward something that might benefit many (commerce, hoarding, what-have-you), vs against something that might result in the arrest of few. The economics I'm thinking of are along the lines of cryptocurrency energy usage per participant, vs image scanning energy per caught perpetrator. The number of caught perpetrators via this method over time will approach zero, but we'll keep using energy to enforce it forever. All this does is remove technology from the problem of child abuse, it doesn't stop child abuse.
dylan604 5y ago
knowing Apple, the initial scan of this will be done while the phone is on charge just like previous versions of scanning your library. However, according to Apple it is just the photos shared with iCloud. So since it's on a charger, it's minimal electron abuse. Once you start adding new content from camera to iCloud, I'd assume the new ML chips of Apple Silicone will be calculating the phashes as part-and-parcel to everything else it does. So unless you're trying to "recreate" known CP, then new photos from camera really shouldn't need this hashing done to them. Only files not originated from the user's iDevice should qualify. If a CP creator is using an iDevice, then their new content won't match existing hashes, so what's that going to do? So so many questions. It's similar yet different to mandatory metal detectors and other screening where 99.99% of people are innocent and "merely" inconvenienced vs the number of people any of that screening catches. Does the mere existence of that screening act as a deterent? That's like asking how many angels can stand on the head of a pin. It's a useless question. The answer can be whatever they want it to be.
axaxs 5y ago
Eh...I don't think of it as one in a trillion scans...but one in a trillion chance per image. I have something like 2000 pics. My wife, at least 5x that number. If we split the difference, and assume the average device has 5000 pics, that's already hitting false positives multiple times. Feel sorry for the first 5 to get their account banned on day 1 because their pic of an odd piece of toast was reported to the govt as cp.
- deleted 5y ago
  [deleted]
wilg 5y ago
Apple claims that metric for a false positive account flagging, not photo matching. > The threshold is set to provide an extremely high level of accuracy and ensures less than a one in one trillion chance per year of incorrectly flagging a given account. https://www.apple.com/child-safety/ https://www.apple.com/child-safety/
- yellow_lead 5y ago
  Good find

KarlKemp 5y ago

Do you really believe that if they scan your photo library at 10am and don't get any false positives, another scan five hours later, with no changes to the library, has the same chance of getting false positives as the first one, independent of that result?

burnished 5y ago
If you take photos, then yes?
NoNotTheDuo 5y ago
Even if the library doesn’t change, doesn’t the possibility of the list of “bad” hashes changing exist? I.e., in your example, a new hash is added to by Apple to the list at 11:30am, and then checked against your unchanged library.
- IfOnlyYouKnew 5y ago
  Oh god have mercy on whatever has happened to these people…

nanidin 5y ago

> Apple has over 1 billion devices. Assuming ten scans per device per day, you would reach one trillion scans in ~100 days. People like to complain about the energy wasted mining cryptocurrencies - I wonder how this works out in terms of energy waste? How many people will be caught and arrested by this? Hundreds or thousands? Does it make economic sense for the rest of us to pay an electric tax in the name of scanning other people's phones for this? Can we claim it as a deductible against other taxes?

FabHK 5y ago
> I wonder how this works out in terms of energy waste? Cryptocurrency waste is vastly greater. It doesn't compare at all. Crypto wastes as much electricity as a whole country. This will lead to a few more people being employed by Apple to verify flagged images, that's it.
- nanidin 5y ago
  In net terms, you're probably right. But at least the energy used for cryptocurrency is being used toward something that might benefit many (commerce, hoarding, what-have-you), vs against something that might result in the arrest of few. The economics I'm thinking of are along the lines of cryptocurrency energy usage per participant, vs image scanning energy per caught perpetrator. The number of caught perpetrators via this method over time will approach zero, but we'll keep using energy to enforce it forever. All this does is remove technology from the problem of child abuse, it doesn't stop child abuse.

dylan604 5y ago

knowing Apple, the initial scan of this will be done while the phone is on charge just like previous versions of scanning your library. However, according to Apple it is just the photos shared with iCloud. So since it's on a charger, it's minimal electron abuse. Once you start adding new content from camera to iCloud, I'd assume the new ML chips of Apple Silicone will be calculating the phashes as part-and-parcel to everything else it does. So unless you're trying to "recreate" known CP, then new photos from camera really shouldn't need this hashing done to them. Only files not originated from the user's iDevice should qualify. If a CP creator is using an iDevice, then their new content won't match existing hashes, so what's that going to do? So so many questions. It's similar yet different to mandatory metal detectors and other screening where 99.99% of people are innocent and "merely" inconvenienced vs the number of people any of that screening catches. Does the mere existence of that screening act as a deterent? That's like asking how many angels can stand on the head of a pin. It's a useless question. The answer can be whatever they want it to be.

axaxs 5y ago

Eh...I don't think of it as one in a trillion scans...but one in a trillion chance per image. I have something like 2000 pics. My wife, at least 5x that number. If we split the difference, and assume the average device has 5000 pics, that's already hitting false positives multiple times. Feel sorry for the first 5 to get their account banned on day 1 because their pic of an odd piece of toast was reported to the govt as cp.

deleted 5y ago
[deleted]

wilg 5y ago

Apple claims that metric for a false positive account flagging, not photo matching. > The threshold is set to provide an extremely high level of accuracy and ensures less than a one in one trillion chance per year of incorrectly flagging a given account. https://www.apple.com/child-safety/ https://www.apple.com/child-safety/

yellow_lead 5y ago
Good find