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I don't think they do. Your phone cryptographically verifies that the software running on the servers is what it says it is, and you can't pull the keys out of

I don't think they do. Your phone cryptographically verifies that the software running on the servers is what it says it is, and you can't pull the keys out of the secure enclave. They also had independent auditors go over the whole thing and publish a report. If the chip is disconnected from the system it will dump its keys and essentially erase all data.

plagiarist 2y ago
I don't understand how publishing cryptographic signatures of the software is a guarantee? How do they prove it isn't keeping a copy of the code to make signatures from but actually running a malicious binary?
- dialup_sounds 2y ago
  The client will only talk to servers that can prove they're running the same software as the published signatures. https://security.apple.com/documentation/private-cloud-compute/softwarelayering#Cloud-Attestation https://security.apple.com/documentation/private-cloud-compu...
  - warkdarrior 2y ago
    And the servers prove that by relying on a key stored in secure hardware. And that secure hardware is designed by Apple, who has a specific interest in convincing users of that attestation/proof. Do you see the conflict of interest now?
HeatrayEnjoyer 2y ago
How do you know the root enclave key isn't retained somewhere before it is written? You're still trusting Apple. Key extraction is difficult but not impossible.
- jsheard 2y ago
  > Key extraction is difficult but not impossible. Refer to the never-ending clown show that is Intels SGX enclave for examples of this. https://en.wikipedia.org/wiki/Software_Guard_Extensions#List_of_SGX_vulnerabilities https://en.wikipedia.org/wiki/Software_Guard_Extensions#List...
- yalogin 2y ago
  Can you clarify what you mean by retained and written?
- abalone 2y ago
  According to Apple, "A randomly generated UID is fused into the SoC at manufacturing time. Starting with A9 SoCs, the UID is generated by the Secure Enclave TRNG during manufacturing and written to the fuses using a software process that runs entirely in the Secure Enclave. This process protects the UID from being visible outside the device during manufacturing and therefore isn’t available for access or storage by Apple or any of its suppliers."[1] But yes of course, you have to trust the manufacturer is not lying to you. PCC is about building on top of that fundamental trust to guard against a whole variety of other attacks. [1] https://support.apple.com/guide/security/secure-enclave-sec59b0b31ff/web https://support.apple.com/guide/security/secure-enclave-sec5...
hnaccount_rng 2y ago
But since they also control the phone's operating system they can just make it lie to you! That doesn't make PCC useless by the way. It clearly establishes that Apple mislead customers, if there is any intentionality in a breach, or that Apple was negligent, if they do not immediately provide remedies on notification of a breach. But that's much more a "raising the cost" kind of thing and not a technical exclusion. Yes if you get Apple, as an organisation, to want to get at your data. And you use an iPhone. They absolutely can.
lmm 2y ago
> you can't pull the keys out of the secure enclave. You or I can't, but that doesn't mean Apple can't. They made that enclave, and put the keys in it in the first place.

plagiarist 2y ago

I don't understand how publishing cryptographic signatures of the software is a guarantee? How do they prove it isn't keeping a copy of the code to make signatures from but actually running a malicious binary?

dialup_sounds 2y ago
The client will only talk to servers that can prove they're running the same software as the published signatures. https://security.apple.com/documentation/private-cloud-compute/softwarelayering#Cloud-Attestation https://security.apple.com/documentation/private-cloud-compu...
- warkdarrior 2y ago
  And the servers prove that by relying on a key stored in secure hardware. And that secure hardware is designed by Apple, who has a specific interest in convincing users of that attestation/proof. Do you see the conflict of interest now?

HeatrayEnjoyer 2y ago

How do you know the root enclave key isn't retained somewhere before it is written? You're still trusting Apple. Key extraction is difficult but not impossible.

jsheard 2y ago
> Key extraction is difficult but not impossible. Refer to the never-ending clown show that is Intels SGX enclave for examples of this. https://en.wikipedia.org/wiki/Software_Guard_Extensions#List_of_SGX_vulnerabilities https://en.wikipedia.org/wiki/Software_Guard_Extensions#List...
yalogin 2y ago
Can you clarify what you mean by retained and written?
abalone 2y ago
According to Apple, "A randomly generated UID is fused into the SoC at manufacturing time. Starting with A9 SoCs, the UID is generated by the Secure Enclave TRNG during manufacturing and written to the fuses using a software process that runs entirely in the Secure Enclave. This process protects the UID from being visible outside the device during manufacturing and therefore isn’t available for access or storage by Apple or any of its suppliers."[1] But yes of course, you have to trust the manufacturer is not lying to you. PCC is about building on top of that fundamental trust to guard against a whole variety of other attacks. [1] https://support.apple.com/guide/security/secure-enclave-sec59b0b31ff/web https://support.apple.com/guide/security/secure-enclave-sec5...

hnaccount_rng 2y ago

But since they also control the phone's operating system they can just make it lie to you! That doesn't make PCC useless by the way. It clearly establishes that Apple mislead customers, if there is any intentionality in a breach, or that Apple was negligent, if they do not immediately provide remedies on notification of a breach. But that's much more a "raising the cost" kind of thing and not a technical exclusion. Yes if you get Apple, as an organisation, to want to get at your data. And you use an iPhone. They absolutely can.

lmm 2y ago

> you can't pull the keys out of the secure enclave. You or I can't, but that doesn't mean Apple can't. They made that enclave, and put the keys in it in the first place.