[josecastillo]

I'm glad someone is talking about this. If you set a passcode, iOS encrypts your data with a key derived, in part, from your passcode and a per-device salt; Apple claims that even with access to the device, a nine digit passcode would take 2.5 years to brute force. [1]

A fingerprint is only useful for authentication, not key derivation, which makes it effectively useless in protecting your secrets from a determined attacker. As it stands today, my data is encrypted with a key that isn't stored on my device. Unless Apple has developed some kind of fingerprint-based key derivation algorithm, that can't be the case for the hapless user who replaces his passcode with a fingerprint scan.

I fear that the innovation announced today is going to make people and their data less safe, not more.

[1]: http://images.apple.com/iphone/business/docs/iOS_Security_Oc...

[m8urn]

"A fingerprint is only useful for authentication, not key derivation"

exactly

[croikle]

> Apple claims that even with access to the device, a nine digit passcode would take 2.5 years to brute force.

That's 2.5 iPhone-years of computation, though. A speedy desktop could be 10 times as fast, and that's before we get to GPUs or multiple machines.