tempest back doors

[Major Variola (ret)]

>Perhaps I am stupid.  I don't know how one would go about modifying
>application software to include a 'back door' that would presumably
>enhance its suceptibility to TEMPEST attacks.  Isn't tempest all about
EM
>spectrum signal detection and capture?

You have your code drive a bus with signal.  The bus radiates, you
'TEMPEST' the signal, game over.  Back in the 60s folks programmed
PDPs to play music on AM radios.  Same thing.  Dig?