5 ms·

This basic implementation fact has been misrepresented over and over and over again. Does anyone read anymore? I’m starting to get really concerned. The hacker

by websites2023 5y ago

This basic implementation fact has been misrepresented over and over and over again. Does anyone read anymore? I’m starting to get really concerned. The hacker community is where I’ve turned to be more informed, away from the clickbait. But I’m being let down.

dmitriid 5y ago
What does "manual review" mean then and how are those images reported?
- shuckles 5y ago
  Before: you would upload images to iCloud Photos. Apple can access your images in iCloud Photos, but it does not. Now: You upload images to iCloud Photos. When doing so, your device also uploads a separate safety voucher for the image. If there are enough vouchers for CSAM matched images in your library, Apple gains the ability to access the data in the vouchers for images matching CSAM. One of the data elements in the voucher is an “image derivative” (probably a thumbnail) which is manually reviewed. If the image derivative also looks like CSAM, Apple files a report with NCMEC’s CyberTip line. Apple can (for now) access the image you stored in iCloud, but it does not. All the data it needs is in the safety voucher. Lot of words spilled on this topic, yet I’d be surprised if a majority of people are even aware of these basic facts about the system operation.
  - matwood 5y ago
    Not sure your before is entirely correct. Apple has admitted to scanning iCloud photos, so they are already accessing them at some point. https://digit.fyi/apple-admits-scanning-photos-uploaded-to-icloud/ https://digit.fyi/apple-admits-scanning-photos-uploaded-to-i...
    - shuckles 5y ago
      The before is entirely correct. Only iCloud Mail was previously scanned for CSAM. As a sanity check: it's not plausible that Apple only generated O(100) referrals to CyberTip annually if it were scanning all iCloud Photos. Other services of similar scale generate O(1M) referrals.
  - munchler 5y ago
    Thank you for this explanation. Much more helpful than any of the lengthy articles I've read to date. I think Apple has botched the rollout of this change by failing to explain clearly how it works. As a result, rumors and misunderstandings have proliferated instead.
  - dmitriid 5y ago
    > access the data in the vouchers for images matching CSAM. One of the data elements in the voucher is an “image derivative” (probably a thumbnail) So the author of the article is technically correct: Apple intentionally uploads CP to their servers for manual review which is explicitly forbidden by law. He even describes the issue with thumbnails
    - shuckles 5y ago
      It is exceedingly unlikely that a system developed with NCMEC’s support and a Fortune 5 legal team somehow fails to comply with the most obviously relevant laws.
      - dmitriid 5y ago
        I'd say: A trillion-dollar company and a government agency can do whatever they feel like, and laws be damned :)
- tgsovlerkhgsel 5y ago
  As I understand it: When you choose to upload your images to iCloud (which currently happens without end-to-end encryption), your phone generates some form of encrypted ticket. In the future, the images will be encrypted, with a backdoor key encoded in the tickets. If Apple receives enough images that were considered a match, the tickets become decryptable (I think I saw Shamir's Secret Sharing mentioned for this step). Right now, Apple doesn't need that because they have unencrypted images, in a future scheme, decrypting these tickets will allow them to decrypt your images. (I've simplified a bit, I believe there's a second layer that they claim will only give them access to the offending images. I have not studied their approach deeply.)
  - shuckles 5y ago
    These are not “claims.” The process by which they get access to only the safety vouchers for images matching CSAM is private set intersection and comes with a cryptographic proof. In no step of the proposal does Apple access the images you store in iCloud. All access is through the associated data in the safety voucher. This design allows Apple to switch iCloud storage to end to end encrypted with no protocol changes.
    - jtc331 5y ago
      What good is end to end encryption if the OS is prebuilt with a method of breaking that encryption? This is definitional backdooring, and you’re back to trusting Apple’s goodwill (and/or willingness to resist governments) to keep your data safe (I.e., not add new decryptable triggers). Not having backdoors is a hard requirement for end to end encryption offering privacy guarantees.
      - shuckles 5y ago
        This is taking the discussion into the realm of hypothetical. If we end up in a world where there are reliable public cloud providers that offer end to end encryption with no content scanning whatsoever, I'll be glad to give them my money.
    - 5y ago
whoknowswhat11 5y ago
Agreed - so dissapointing. The idea that standard moderation steps are a felony is such a stretch. Almost all the major players have folks doing content screening and management - and yes, this may invovle the provider transmitting / copying etc images that are then flagged and moderated away. The idea that this is a felony is rediculous. The other piece is that folks are making a lot of assumptions about how this works, then claiming things are felonies. Does it not strain credibility slightly that apple, with it's team of lawyers, has decided to instead of blocking CASM to commit CASM felonies? And the govt is going to bust them for this? Really? They are doing what govt wants and using automation to drive down the number of images someone will look at and what even might get transferred to apple's servers in the first place.
- msandford 5y ago
  Does the law have a moderation carve out? There are plenty of laws that have what's called 'strict liability' where your intent doesn't matter. I'm not suggesting that this is absolutely positively a situation where strict liability exists and that moderation isn't allowed. But the idea that "hey we're trying to do the right thing here" will be honored in court is....not obvious.
  - whoknowswhat11 5y ago
    If we investigated this author if they do in fact run a photo service we would inevitably find that unless they are incompetent they have to moderate content, either blind or based on flags. So if apple is going to jail for child porn because they moderate / report content after flagging (this is normally actually required to do - report it), then this article writer should be going to jail as well - I guarantee his services stores, forwards and otherwise handles CASM content. My complaint is just - HN used to focus on stuff where folks didn't just always jump to worst case arguments (ie, apple is guilty of child porn and is committing felonies) without at least allowing that apple MAY have given this a tiny bit of thought. It's just tiresome to wade through. It's a mashup of they are blocking too much, are the evil govt henchperson to they are breaking the law and going to jail for felony child porn charges. I get that it generates interaction (here I am), but it's annoying after a while. Clickbait sells though no question so things like "One Bad Apple" are probably going to keep on coming at us.
alisonkisk 5y ago
There's a weird meme I the hacker community that law enforcement has no right to use any means to enforce the law, and can only bust people who turn themselves in.

dmitriid 5y ago

What does "manual review" mean then and how are those images reported?

shuckles 5y ago
Before: you would upload images to iCloud Photos. Apple can access your images in iCloud Photos, but it does not. Now: You upload images to iCloud Photos. When doing so, your device also uploads a separate safety voucher for the image. If there are enough vouchers for CSAM matched images in your library, Apple gains the ability to access the data in the vouchers for images matching CSAM. One of the data elements in the voucher is an “image derivative” (probably a thumbnail) which is manually reviewed. If the image derivative also looks like CSAM, Apple files a report with NCMEC’s CyberTip line. Apple can (for now) access the image you stored in iCloud, but it does not. All the data it needs is in the safety voucher. Lot of words spilled on this topic, yet I’d be surprised if a majority of people are even aware of these basic facts about the system operation.
- matwood 5y ago
  Not sure your before is entirely correct. Apple has admitted to scanning iCloud photos, so they are already accessing them at some point. https://digit.fyi/apple-admits-scanning-photos-uploaded-to-icloud/ https://digit.fyi/apple-admits-scanning-photos-uploaded-to-i...
  - shuckles 5y ago
    The before is entirely correct. Only iCloud Mail was previously scanned for CSAM. As a sanity check: it's not plausible that Apple only generated O(100) referrals to CyberTip annually if it were scanning all iCloud Photos. Other services of similar scale generate O(1M) referrals.
- munchler 5y ago
  Thank you for this explanation. Much more helpful than any of the lengthy articles I've read to date. I think Apple has botched the rollout of this change by failing to explain clearly how it works. As a result, rumors and misunderstandings have proliferated instead.
- dmitriid 5y ago
  > access the data in the vouchers for images matching CSAM. One of the data elements in the voucher is an “image derivative” (probably a thumbnail) So the author of the article is technically correct: Apple intentionally uploads CP to their servers for manual review which is explicitly forbidden by law. He even describes the issue with thumbnails
  - shuckles 5y ago
    It is exceedingly unlikely that a system developed with NCMEC’s support and a Fortune 5 legal team somehow fails to comply with the most obviously relevant laws.
    - dmitriid 5y ago
      I'd say: A trillion-dollar company and a government agency can do whatever they feel like, and laws be damned :)
tgsovlerkhgsel 5y ago
As I understand it: When you choose to upload your images to iCloud (which currently happens without end-to-end encryption), your phone generates some form of encrypted ticket. In the future, the images will be encrypted, with a backdoor key encoded in the tickets. If Apple receives enough images that were considered a match, the tickets become decryptable (I think I saw Shamir's Secret Sharing mentioned for this step). Right now, Apple doesn't need that because they have unencrypted images, in a future scheme, decrypting these tickets will allow them to decrypt your images. (I've simplified a bit, I believe there's a second layer that they claim will only give them access to the offending images. I have not studied their approach deeply.)
- shuckles 5y ago
  These are not “claims.” The process by which they get access to only the safety vouchers for images matching CSAM is private set intersection and comes with a cryptographic proof. In no step of the proposal does Apple access the images you store in iCloud. All access is through the associated data in the safety voucher. This design allows Apple to switch iCloud storage to end to end encrypted with no protocol changes.
  - jtc331 5y ago
    What good is end to end encryption if the OS is prebuilt with a method of breaking that encryption? This is definitional backdooring, and you’re back to trusting Apple’s goodwill (and/or willingness to resist governments) to keep your data safe (I.e., not add new decryptable triggers). Not having backdoors is a hard requirement for end to end encryption offering privacy guarantees.
    - shuckles 5y ago
      This is taking the discussion into the realm of hypothetical. If we end up in a world where there are reliable public cloud providers that offer end to end encryption with no content scanning whatsoever, I'll be glad to give them my money.
  - 5y ago

whoknowswhat11 5y ago

Agreed - so dissapointing. The idea that standard moderation steps are a felony is such a stretch. Almost all the major players have folks doing content screening and management - and yes, this may invovle the provider transmitting / copying etc images that are then flagged and moderated away. The idea that this is a felony is rediculous. The other piece is that folks are making a lot of assumptions about how this works, then claiming things are felonies. Does it not strain credibility slightly that apple, with it's team of lawyers, has decided to instead of blocking CASM to commit CASM felonies? And the govt is going to bust them for this? Really? They are doing what govt wants and using automation to drive down the number of images someone will look at and what even might get transferred to apple's servers in the first place.

msandford 5y ago
Does the law have a moderation carve out? There are plenty of laws that have what's called 'strict liability' where your intent doesn't matter. I'm not suggesting that this is absolutely positively a situation where strict liability exists and that moderation isn't allowed. But the idea that "hey we're trying to do the right thing here" will be honored in court is....not obvious.
- whoknowswhat11 5y ago
  If we investigated this author if they do in fact run a photo service we would inevitably find that unless they are incompetent they have to moderate content, either blind or based on flags. So if apple is going to jail for child porn because they moderate / report content after flagging (this is normally actually required to do - report it), then this article writer should be going to jail as well - I guarantee his services stores, forwards and otherwise handles CASM content. My complaint is just - HN used to focus on stuff where folks didn't just always jump to worst case arguments (ie, apple is guilty of child porn and is committing felonies) without at least allowing that apple MAY have given this a tiny bit of thought. It's just tiresome to wade through. It's a mashup of they are blocking too much, are the evil govt henchperson to they are breaking the law and going to jail for felony child porn charges. I get that it generates interaction (here I am), but it's annoying after a while. Clickbait sells though no question so things like "One Bad Apple" are probably going to keep on coming at us.

alisonkisk 5y ago

There's a weird meme I the hacker community that law enforcement has no right to use any means to enforce the law, and can only bust people who turn themselves in.