Every SCIF has a unique identification (UID) based on its full
   spectrum of construction materials, dimensions and MEP
   characteristics. Each compromises itself by inadvertent
   signals, or rather signals not usually or easily intercepted.
   Same for each building and building site above and below
   the surface.
   Conventional SCIF design characteristics which are in the
   public domain do not cover the full spectrum, typically
   only the EM. Like CryptoAG and other ruses, SCIFs are
   quite collectible behind the EM mask.
   Similarly, TEMPEST characteristics which are in the public
   domain do not cover the full spectrum of collectible
   signals and metrics of compromising emanations.
   Some similarity to lie detection ruses.
   There are likely other ruses, as customary comsec
   disinformation hardly restricted to crypto.
   Now could that be what BadBIOS is up to? A leak of
   disinfo for those which have limited interception and
   analysis equipment? Still, it is a fine story about the many
   levels of comsec onion ot be peeled.
   At 09:52 AM 11/1/2013, you wrote:

          > perhaps i misunderstand it, though must 'resonance'
          > be audibly acoustic, and would a SCIF actually defend
          > against "vibrations" at all frequencies.

     the question highlights how ill-suited the 'spy agencies'​​ are for
     conducting asymmetric anything.
     Unless they had a Brain inside think of a mechanism and explain it
     to an Engineer to propose to a Facilities Security Manager who
     obtained confirmation from a Director, they would be vulnerable.
     For instance, TEMPEST security - every SCIF has it because inside it
     was well documented/implemented. SEISMIC security - no SCIF*** is
     isolated from seismic vibrations modulated with data. So, to
     ex-filtrate data, have those passing circus elephants stomp their
     feet in predetermined patterns. Or make one of those "Dune" style
     thumpers. The worms in this case being .... ?
     *** I'm suppose some very few SCIFs are vibration isolated for
     various reasons, but not as an exfil channel.
     -daniel