Robert B. wrote:
> As an example, lets say you are at work and go to the restroom,
> leaving your keys on your desk.  While you're gone for 5 minutes no
> coworker could get your ibutton, drive to your residence, gain
> access, and return the keys such that you would not notice.  But 5
> minutes is more than enough to copy the serial number for use at a
> later time.

There is no need for this to be true.  Presumably the key would be trained
with the secret while the user had physical access to the lock.  The code
would then live in the key in the PIC RAM or read-protected EEPROM or the
like.  This can be cracked with enough effort, but not casually in 5 minutes
and keeping the device physically unharmed so that you're not alerted.

It seems you are worrying about the .1% security hole and ignoring the 50%
security hole that is the glass window next to the door.  That only takes 5
seconds and a low tech brick to get around.


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