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Comment by tlrobinson | Hacker News Reader

Why kind of phone is this? I believe iPhones don't allow unlocking with TouchID after 24 hours of inactivity, presumably for this reason...

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Could just be that the police don't know this, and they'll get a rude surprise when they go and try it.

Not that it's important, but I believe it's 48 hours, and 8 hours if you haven't entered your passcode in the last six days. You also only get five tries, so a finger that is sometimes recognized but not with great reliability would still probably fail.

Correct, rules outlined here: http://www.macworld.com/article/3072181/ios/new-touch-id-rul...

• Not unlocked for 8 hours after not having used passcode for 6 days

• Not unlocked for 48 hours otherwise

• Restarted

• 5 failed fingerprints

• Enrolling new fingerprints

Well, does the OS or the fingerprint TPM handle the timeout?

If the OS handles it (and potentially if the OS files themselves aren't completely and fully encrypted) then you can trick the OS into thinking it hasn't been 24-48 hours - all you need is for the fingerprint TPM to keep returning 'success'. If the TPM handles it then it is slightly harder to do.

IIRC the Secure Enclave handles it.

Important to note as well that the fingerprint sensor unlock is not protected by the 5th amendment like passwords are. [1]

[1]http://www.theatlantic.com/technology/archive/2016/05/iphone...

Which, IMHO, is perfectly reasonable. Your fingerprints are used by the government for /identification/, just like your driver's license. It's not a password. You are required to surrender your fingerprints when you are arrested. It's not compelled speech because it's an identification marker, not a password.

If you do have a runin with the police, just reboot your phone by holding down the power and home button for 10 seconds. Or, if you actually have something to hide, just don't use Touch ID.

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