Private data protection.

[Christoph Fink]

Ilja O. wrote:
> 1) Auth using PIN number (this requires encrypted image presence in
> phone file system by it's boot time end -- not reallyl convenient if
> SD card is used).
>   
IMO encrypting Data with the PIN Number is not such a good thing, 
because the possibilities of different keys are definately not high (max 
8 digits, only numbers). A better solution would be to save the PIN on 
the encrypted storage and automatically read it.
> 2) Auth using key file accessible on network (when phone is connected
> to your computer or local network). This means that auth can be
> performed only in your place (home, work...).
>   
Not such a good solution for a Phone IMO (if you're in holidays without 
laptop for example)
> 3) Auth using presence of another bluetooth or WiFi device (the MAC
> address of this device is used as key). This means that phone fully
> unlocks when your bluetooth mouse or router are around. ;)
>
>   
Same here...

The most secure Thing IMO would be to ask a passprase while booting 
(maybe hack uboot for that, if it doesn't know that) or put data on 
another device/partition then the OS and asking later for the passphrase 
(maybe easier to implement)