[Freedombox-discuss] Without software collusion

[timschmidt@gmail.com (Tim Schmidt)]

On Thu, Jun 28, 2012 at 4:44 PM, Tim Schmidt <timschmidt at gmail.com> wrote:
> Covert communication through the power supply by artificially loading
> the GPU (CPUs are too obvious), to spike power usage in such a way as
> to produce morse code dots and dashes someone could only decode if
> they knew they were there, and monitoring the power usage of the
> machine is out of band.
>
> Sending an ethernet frame is just sending an ethernet frame.

I hope you can see the difference --

For the covert power supply communication, there are no rules.  Send
whatever information you want.

For the ethernet frame, you still have to obey all the rules imposed
by the ethernet equipment between you and the target machine.  Rules
which offer significant protections.

--tim