"We make the hardware and we pinky promise that we will protect your data and will open source part of it" means nothing for privacy. Especially when things like warrants come into play.
iOS won't send any data to a PCC that isn't running a firmware that's been made public in their transparency logs and compute nodes have no way to be debugged in a way that exposes user data[1]
And at the end of the day, this is going to give the warrant holder a handful of requests from a specific user? Why wouldn't they use that same warrant to get onto the target's device directly and get that same data plus a ton more?
0: https://help.apple.com/pdf/security/en_US/apple-platform-sec... 1: https://security.apple.com/blog/private-cloud-compute/
Warrants to hack devices are a lot less common and generally harder to obtain. That's why police will send Google warrants for "give us info on every device who has been in a radius of x between y and z time".
I'm sure Apple did their very best to protect their users, but I don't think their very best is good enough to warrant this kind of trust. A "secure cloud" solution will also tempt future projects to use the cloud over local processing more, as cloud processing is now readily available. Apple's local processing is a major advantage over the competition but I doubt that'll stay that way if their cloud solution remains this integrated.
Your example indicates a situation where law enforcement does not know which device belongs to their suspect, if they even have one. That's a very different scenario from a targeted "tell us the requests belonging to this individual".
Warrants to search a device are extremely common place, otherwise the likes of Grayshift and Cellebrite would not be around.
From a threat modeling perspective compromising PCC is high risk (Apple's not just going to comply and the fight will be very public, see the FBI San Bernardino fight) , high effort (Long protracted court case), low reward (I only see requests that are going to get shipped off to the cloud). If I were law enforcement I'd explore every other avenue available to me before I go down that particular rabbit hole which is exactly what this design is intended to achieve.
At least with gmail and chat clients etc. things are somewhat put in compartments, one of the services might screw up and do something with your emails but your Messenger or WhatsApp chats are not affected by that, or vice versa. But when you bake it into the OS (laptop or phone) you're IMHO taking a much bigger risk, no matter what the intentions are.
Whereas with apps like Gmail and WhatsApp on an iPhone, you must trust Google and Meta in addition to Apple, not in place of Apple. It doesn't distribute who you trust, it multiplies it.
In essence, what you're doing is training an assistant to learn all of your details of your life and habits and the question is if that "assistant" is really secure forever. Taken to the extreme, the assistant becomes a sort of "backup" of yourself. But yeah it's an individual decision with the pro's and con's of this.
Yeah, pretty much
Also, your grandma might not setup a VM, but it sounds like the off-device processing is essentially stateless, or at most might have a very lightweight session. It seems like the kind of thing one person could setup for their family (with the same tamper-proof signatures, plus physical security), or provide a privacy focused appliance for anyone to just plug into a wall, if they wanted to.
There have been many cases recently of compromised code being in the wild for quite some time and then only known about by accident.
Auditing helps the company writing it, the auditors are usually experts in breaking stuff in fun ways, and it's good for business - we could slap "code security audited by XXX" on the sales pitch.
You're on the precipice of discovering the problem of incentives when it comes to audits.
Audits are good, but they're inferior to source available
I have no idea what code is running on a server I can't access. I can't exactly go SSH into siri.apple.com and match checksums. Knowing Apple's control freak attitude, I very much doubt any researcher permitted to look at their servers is going to be very independent either.
Apple is just as privacy friendly as ChatGPT or Gemini. That's not necessarily a bad thing! AI requires feeding lots of data into the cloud, that's how it works. Trying to sell their service as anything more than that is disingenuous, though.
That's like... the whole point? You have some kind of hardware-based measured boot thing that can provide a cryptographic attestation that the code it's running is the same as the code that's been reviewed by an independent auditor. If the auditor confirms that the data isn't being stored, just processed and thrown away, that's almost as good as on-device compute for 99.999% of users. (On-device compute can also be backdoored, so you have to trust this even in the case that everything is local.)
The presentation was fairly detail-light so I don't know if this is actually what they're doing, but it's nice to see some effort in this direction.
E: I roughly agree with this comment (https://news.ycombinator.com/item?id=40638740) later down the thread -- what exactly the auditors are verifying is the key important bit.
Apple has developed some of the strongest anti tampering compute on existence to prevent people from running code they don't want on hardware they produce. However, that protection is pretty useless when it comes to protection from Apple. They have the means to bypass any layer of protection they've built into their hardware.
It all depends on what kind of auditing Apple will allow. If Apple allows anyone to run this stuff on any Mac, with source or at least symbols available, I'll give it the benefit of the doubt. If Apple comes up with NDAs and limited access, I won't trust them at all.
Signal has the added benefit that it doesn't need to read what's in the messages you send. It needs some very basic routing information and the rest can be encrypted end to end. With AI stuff, the contents need to be decrypted in the cloud, so the end-to-end protections don't apply.
Apple's thrown stones come back to hunt their glass ceiling.
Secure enclave stuff can be used to build a trust relationship if it's designed well, but Apple is the party hosting the service and the one burning the private keys into the chip.