4 ms·
That doesn’t work as well because the counter is kept in the Secure Enclave so it’s not part of the flash contents. Also the exponential delay in attempts is en
by giovannibajo1 9y ago
That doesn’t work as well because the counter is kept in the Secure Enclave so it’s not part of the flash contents. Also the exponential delay in attempts is enforced by the enclave.
Previous iOS versions used to have some small window where you could race and power off after trying a passcode but before the enclave had incremented the counter, but that bug was fixed long ago. Maybe there are others unknown bugs of similar kind
- gruez 9y ago>That doesn’t work as well because the counter is kept in the Secure Enclave so it’s not part of the flash contents I skimmed the secure enclave documentation at https://www.apple.com/business/docs/iOS_Security_Guide.pdf https://www.apple.com/business/docs/iOS_Security_Guide.pdf (page 5, 14, 15), and I can't find anything to confirm that.
- Scoundreller 9y agoIt makes the most sense that it's in the Secure Enclave. Once you have control of the counter, you can run through the passphrase space in no time.
- tinus_hn 9y agoOnly if the pass’phrase’ is a short numeric code. iOS also allows a normal password.
- Godel_unicode 9y ago"On devices with Secure Enclave, the delays are enforced by the Secure Enclave coprocessor." Page 15 It was also confirmed explicitly during the Q&A at the blackhat talk in 2016, which I believe is on YouTube.
- gruez 9y ago>It was also confirmed explicitly during the Q&A at the blackhat talk in 2016, which I believe is on YouTube. doesn't look like it. https://www.blackhat.com/docs/us-16/materials/us-16-Mandt-Demystifying-The-Secure-Enclave-Processor.pdf https://www.blackhat.com/docs/us-16/materials/us-16-Mandt-De...
- Godel_unicode 9y agoThat’s not the apple talk. Apple gave a talk specifically about hardware security in the iPhone. Edit: this one. https://youtu.be/BLGFriOKz6U https://youtu.be/BLGFriOKz6U Edit 2: the question was asked at 47:20