7 ms·

I'm too lazy to find a link for it, but last time I read about Cellebrite, they were cloning the data and simply trying unlock codes in sequence until one worke

I'm too lazy to find a link for it, but last time I read about Cellebrite, they were cloning the data and simply trying unlock codes in sequence until one worked. They could restore the cloned data before each try, or possibly do it on custom hardware or an emulator, and start with a fresh copy each time, so they never triggered "erase after 10 failures". It's a pretty straightforward approach, but it doesn't scale well. Works for targeted cracking of high-value targets.

pls2halp 9y ago
As far as I can remember, that was the proof of concept which ended up emerging for the 5C crack a few years ago, and I don’t see any reason the methods would’ve changed.
- brandon 9y ago
  The iPhone 5C could be attacked this way because it didn't contain the Secure Enclave that shipped as part of the A7 chip. Attacks on devices with the A7 (or newer chips) would be novel.
eugeniub 9y ago
This is not true. You cannot just clone the data and run passcodes against it, because the data is not encrypted by your passcode. Instead, each file on iOS 11 is encrypted with a different AES 256-bit key, and cracking even one 256-bit key through exhaustive search is thought to be out of reach of humankind (https://security.stackexchange.com/questions/6141/amount-of-simple-operations-that-is-safely-out-of-reach-for-all-humanity/6149#6149 https://security.stackexchange.com/questions/6141/amount-of-...). The file keys are wrapped by, among other things, the device's Unique ID, a 256-bit key generated by the Secure Enclave, and accessible only to the Secure Enclave, not any other hardware or software running on an iOS device. In the end, the only options are: bruteforcing passcodes on the original device while attempting to trick the device into allowing more than 10 failures, or prying open the Secure Enclave to obtain the Unique ID — both options a lot more complicated than just cloning the data and trying passcodes on it.
- userbinator 9y ago
  or prying open the Secure Enclave to obtain the Unique ID People have been cracking secure coprocessors of the type used in payment cards, TPMs, and the like for a long time, dare I say even those which were designed to a higher level of security than Apple's. The fact that there is an entire phone attached to it doesn't make much of a difference, but the technology behind this (FIB, microprobing, etc.) has been steadily dropping in price and increasing in availability for a long time.
  - Scoundreller 9y ago
    > but the technology behind this (FIB, microprobing, etc.) has been steadily dropping in price Isn't it more of a cat and mouse? The defences also drop in price and increase in availability? As usual, old tech is becomes vulnerable. Hopefully most people will get the chance to upgrade to the latest and greatest before attacks get too easy and destroy the old device. I wonder what Chris Tarnovsky is up to these days...
  - Godel_unicode 9y ago
    Fwiw, Apple has a $100k bounty on this type of exploit (pulling secrets from the secure enclave).
    - anilgulecha 9y ago
      I'm sure companies, like the one in the article, will pay substantially more for them.
    - OkGoDoIt 9y ago
      But Cellebrite apparently makes millions off of its service, so the economic incentives are still on their side.
      - movedx 9y ago
        I understand what you're saying here: why share the fact they've broken the SE for $100k when they can keep making millions. But if they cracked the SE, and kept that fact to themselves, they would be making even more money because every government on the planet would be coming to them. This is provided they kept it to themselves. It would mean a significant spike in the number of phones being cracked and people being arrested/charged/hung/etc. This would be a statistic that would jump off the charts and trigger Apple to essentially develop a solution straight away. The only way this would work is if they had cracked the SE and are doing an Enigma: keeping it top secret and only cracking very high profile targets with the technology, which I guess is possible.
StreamBright 9y ago
Doesn't scale well? Are you assuming you cannot run this parallel?

pls2halp 9y ago

As far as I can remember, that was the proof of concept which ended up emerging for the 5C crack a few years ago, and I don’t see any reason the methods would’ve changed.

brandon 9y ago
The iPhone 5C could be attacked this way because it didn't contain the Secure Enclave that shipped as part of the A7 chip. Attacks on devices with the A7 (or newer chips) would be novel.

eugeniub 9y ago

This is not true. You cannot just clone the data and run passcodes against it, because the data is not encrypted by your passcode. Instead, each file on iOS 11 is encrypted with a different AES 256-bit key, and cracking even one 256-bit key through exhaustive search is thought to be out of reach of humankind (https://security.stackexchange.com/questions/6141/amount-of-simple-operations-that-is-safely-out-of-reach-for-all-humanity/6149#6149 https://security.stackexchange.com/questions/6141/amount-of-...). The file keys are wrapped by, among other things, the device's Unique ID, a 256-bit key generated by the Secure Enclave, and accessible only to the Secure Enclave, not any other hardware or software running on an iOS device. In the end, the only options are: bruteforcing passcodes on the original device while attempting to trick the device into allowing more than 10 failures, or prying open the Secure Enclave to obtain the Unique ID — both options a lot more complicated than just cloning the data and trying passcodes on it.

userbinator 9y ago
or prying open the Secure Enclave to obtain the Unique ID People have been cracking secure coprocessors of the type used in payment cards, TPMs, and the like for a long time, dare I say even those which were designed to a higher level of security than Apple's. The fact that there is an entire phone attached to it doesn't make much of a difference, but the technology behind this (FIB, microprobing, etc.) has been steadily dropping in price and increasing in availability for a long time.
- Scoundreller 9y ago
  > but the technology behind this (FIB, microprobing, etc.) has been steadily dropping in price Isn't it more of a cat and mouse? The defences also drop in price and increase in availability? As usual, old tech is becomes vulnerable. Hopefully most people will get the chance to upgrade to the latest and greatest before attacks get too easy and destroy the old device. I wonder what Chris Tarnovsky is up to these days...
- Godel_unicode 9y ago
  Fwiw, Apple has a $100k bounty on this type of exploit (pulling secrets from the secure enclave).
  - anilgulecha 9y ago
    I'm sure companies, like the one in the article, will pay substantially more for them.
  - OkGoDoIt 9y ago
    But Cellebrite apparently makes millions off of its service, so the economic incentives are still on their side.
    - movedx 9y ago
      I understand what you're saying here: why share the fact they've broken the SE for $100k when they can keep making millions. But if they cracked the SE, and kept that fact to themselves, they would be making even more money because every government on the planet would be coming to them. This is provided they kept it to themselves. It would mean a significant spike in the number of phones being cracked and people being arrested/charged/hung/etc. This would be a statistic that would jump off the charts and trigger Apple to essentially develop a solution straight away. The only way this would work is if they had cracked the SE and are doing an Enigma: keeping it top secret and only cracking very high profile targets with the technology, which I guess is possible.

StreamBright 9y ago

Doesn't scale well? Are you assuming you cannot run this parallel?