[Gnuk-users] Flashing the FST-01 and generating and importing a key in a secure environment

[NdK]

Il 17/02/2015 03:02, NIIBE Yutaka ha scritto:
> On 02/16/2015 06:15 PM, Jonathan Schleifer wrote:
>> Flashing the firmware would erase all keys, right?
> Yes.
..."Under standard circumstances".
See the many flaws some PICs had (power/clock glitches during erase to
avoid deleting the flash before resetting the protection fuse). Or maybe
more invasive attacks (decapping & similar) could expose the protection
bit and reset it... Quite useless since the keys are encrypted with user
PIN (unless the firmware have been replaced, but then there are *way*
simpler attacks!).
Maybe one unaddressed issue is RAM "burning": if you keep the same data
in the same RAM location for a long time, the electrical levels change
slightly and can be recognized even after a long time. IIRC this issue
have been addressed quite in depth by one of Ross Anderson's works.

> No, transparent shrink tube couldn't prevent such an attack, either.
> It only makes it difficult a bit.  However, it requires physical
> modification/recovery, which would be more guilty under some
> legislation.
I think that if you are the target of such an attack, then you've
already lost: you can't trust anything.
As I learnt in OpenAlarm, security is just a compromise between costs:
cost of defense (that depends on the cost of a failure in the security
system) vs cost of attack.

BYtE,
 Diego