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NPR was playing this story up as if it's a blow for Apple - is it really? Isn't the vulnerability the fact that the phone has no secure enclave, and so the time

NPR was playing this story up as if it's a blow for Apple - is it really? Isn't the vulnerability the fact that the phone has no secure enclave, and so the timeout/wipe can be worked around by external access to the flash? Isn't that the whole reason the newer phones were upgraded? Older device fails, newer device with improved security doesn't. That's not a blow to Apple, that's the way the world works.

chillingeffect 11y ago
You are exactly right: If the vulnerability does exist, and the FBI did contract it out, this just shows that the vulnerability is very expensive and only available to major state actors. In fact, a single government - the U.S. - couldn't do it alone. It's possible this is a actually script-kiddie exploitable vuln, but I highly doubt it. All that we have learned is what we suspected: Some "outdated"/older phones are infinitesimally less secure in a way that only internationally collaboration between some of the world's most powerful hackers can break. And it's not really the FBI's fault. They're not sharing it with anyone. (Probably). So it's not a blow to Apple at all. They already moved on before this. This phone/vuln was a stepping stone for them that is already obsolete. In fact, this is a boon to Apple, bc people will be scared into upgrading. (Except for the hopeless sheeple who "have nothing to hide" and perfer to share their personal info with the world's gubmints).
mikeash 11y ago
As far as I've been able to figure out, the Secure Enclave does not have its own storage. The proposed attack of cloning the phone's flash memory would work just as well on a new iPhone 6s. A lot of people are assuming that the Secure Enclave would prevent this attack, but I've not yet been able to find any basis for that assumption. The main security advantage of newer phones in this context is that Touch ID makes it practical to set a more complex passphrase. The flash cloning attack only works if you have a short passcode set, because it relies on brute force. If your passphrase is complex enough that it can't be brute forced even when the software controls are removed, then you're still safe. I'd wager that when the iPhone 7 ships this fall, it will have an upgraded Secure Enclave with internal storage that can prevent this attack entirely.
- Karunamon 11y ago
  That's absolutely correct, come to find out. For some reason I thought the SE was responsible for holding some of the keys and the wipe counter, but instead it's a section of the NAND flash called "Effaceable Storage". Their own whitepaper defines it: A dedicated area of NAND storage, used to store cryptographic keys, that can be addressed directly and wiped securely. While >>it doesn’t provide protection if an attacker has physical possession of a device<<, keys held in Effaceable Storage can be used as part of a key hierarchy to facilitate fast wipe and forward security (emphasis mine) However, it appears that the FBI attack only worked because the people in question used the 4 digit pin. A strong passcode is the way to go and protects you from these kinds of brute force attacks.
  - mikeash 11y ago
    I initially assumed the same as you, because it would just make so much sense. And yes, it looks like all of this came down to the short PIN. It's likely a six-digit PIN would still fall, but a proper passcode would have made this whole affair moot. It looks like even the older phones are still totally secure in that case, although the lack of Touch ID can make it somewhat impractical. This is a major problem I have with the "iPhones got less secure" idea. Apple has gone through heroics to make short passcodes somewhat secure, but there's only so much you can reasonably expect there.
danielweber 11y ago
For all we know, it was because the device was owned by San Bernadino government (despite the FBI screwing that up) that allowed them to access it. This is all smoke and no fire.

chillingeffect 11y ago

You are exactly right: If the vulnerability does exist, and the FBI did contract it out, this just shows that the vulnerability is very expensive and only available to major state actors. In fact, a single government - the U.S. - couldn't do it alone. It's possible this is a actually script-kiddie exploitable vuln, but I highly doubt it. All that we have learned is what we suspected: Some "outdated"/older phones are infinitesimally less secure in a way that only internationally collaboration between some of the world's most powerful hackers can break. And it's not really the FBI's fault. They're not sharing it with anyone. (Probably). So it's not a blow to Apple at all. They already moved on before this. This phone/vuln was a stepping stone for them that is already obsolete. In fact, this is a boon to Apple, bc people will be scared into upgrading. (Except for the hopeless sheeple who "have nothing to hide" and perfer to share their personal info with the world's gubmints).

mikeash 11y ago

As far as I've been able to figure out, the Secure Enclave does not have its own storage. The proposed attack of cloning the phone's flash memory would work just as well on a new iPhone 6s. A lot of people are assuming that the Secure Enclave would prevent this attack, but I've not yet been able to find any basis for that assumption. The main security advantage of newer phones in this context is that Touch ID makes it practical to set a more complex passphrase. The flash cloning attack only works if you have a short passcode set, because it relies on brute force. If your passphrase is complex enough that it can't be brute forced even when the software controls are removed, then you're still safe. I'd wager that when the iPhone 7 ships this fall, it will have an upgraded Secure Enclave with internal storage that can prevent this attack entirely.

Karunamon 11y ago
That's absolutely correct, come to find out. For some reason I thought the SE was responsible for holding some of the keys and the wipe counter, but instead it's a section of the NAND flash called "Effaceable Storage". Their own whitepaper defines it: A dedicated area of NAND storage, used to store cryptographic keys, that can be addressed directly and wiped securely. While >>it doesn’t provide protection if an attacker has physical possession of a device<<, keys held in Effaceable Storage can be used as part of a key hierarchy to facilitate fast wipe and forward security (emphasis mine) However, it appears that the FBI attack only worked because the people in question used the 4 digit pin. A strong passcode is the way to go and protects you from these kinds of brute force attacks.
- mikeash 11y ago
  I initially assumed the same as you, because it would just make so much sense. And yes, it looks like all of this came down to the short PIN. It's likely a six-digit PIN would still fall, but a proper passcode would have made this whole affair moot. It looks like even the older phones are still totally secure in that case, although the lack of Touch ID can make it somewhat impractical. This is a major problem I have with the "iPhones got less secure" idea. Apple has gone through heroics to make short passcodes somewhat secure, but there's only so much you can reasonably expect there.

danielweber 11y ago

For all we know, it was because the device was owned by San Bernadino government (despite the FBI screwing that up) that allowed them to access it. This is all smoke and no fire.