Re: spyproofing your house/work building

> Drapes so the lip readers can't see you.

   Make sure the drapes block IR.  There are instances of even local
   police forces flooding the front of a house with IR light, and
   viewing the activities inside with IR viewers -- all of this
   through closed drapes.

Or you could just put a nice incandescent light fixture between you and the
drapes; nice IR output from those bulbs. Halogen fixtures ought to work
also, but fluorescent bulbs don't produce enough IR.

More importantly: attach a contact-speaker to each pane of glass, and feed
Top 40 radio to it. There have been reported cases of spy types bouncing
laser beams off windows and using the reflected beams to reproduce the
vibrations produced in the glass by reflected sound; in other words, the
window panes are large membranes which vibrate in sync with the sound that
hits them, so you want to override those vibrations with something else.

This reeks of paranoia, eh?

Jazz

> Or you could just put a nice incandescent light fixture between you and the
> drapes; nice IR output from those bulbs. Halogen fixtures ought to work
> also, but fluorescent bulbs don't produce enough IR.

Might not work as the incandescent light source still won't stop the
window from vibrating.  They can still reflect a laser off it regardless
of the output of another source.  They may have tweak their amps... but
it won't help against it.
 
> More importantly: attach a contact-speaker to each pane of glass, and feed
> Top 40 radio to it. There have been reported cases of spy types bouncing
> laser beams off windows and using the reflected beams to reproduce the
> vibrations produced in the glass by reflected sound; in other words, the
> window panes are large membranes which vibrate in sync with the sound that
> hits them, so you want to override those vibrations with something else.

Won't work.  You need a random, independant source of noise.  Each
window pane should have its own noise source attached to a speaker.
If the speaker is tuned into a radio station, they too can tune into
the same station, then substract the two signals giving them a fairly
clear ear to listen in from.  A random noise source that is independant
will do well because they can't substract it out.  If two windows in
two different rooms also use the same random noise, they can differentiate
between the two rooms and get the sound.

I suppose they could bounce four or five lasers on the same window in
hopes of being able to use two beams for the substraction, but if the
speaker is placed in a good location, or several of them are placed
on the same window, they'll have a bitch of a time getting anything.

In that case they'll probably resort to using microwaves to bounce off
a metal item in the room which would also vibrate with any sounds in the
room.  The only real defense against that would be strong shielding
and a microwave detector to see if the shielding failed... the shielding
has to be sound isolated or else the walls of the shielding could be
used to get sound.. :-(  Pretty nasty shit, eh?
 
> This reeks of paranoia, eh

Nope, it's da truth. :-)  I'm not doing this out of paranoia.  I'm
learning about this incase the police state comes anytime soon.  It's
far better to learn about it before than after it's too late.

I don't want to stop the fun Jason Zions and Arsen Ray A. are having, but
their ideas won't work. Not that I think IR surveillance is the
highest priority to worry about, either.

But I used to be a physicist, and some of the reasoning here is
perpetuating fallacies:

> > Or you could just put a nice incandescent light fixture between you and the
> > drapes; nice IR output from those bulbs. Halogen fixtures ought to work
> > also, but fluorescent bulbs don't produce enough IR.

Nope. Incandescent bulbs will have a broad spectrum of IR, from the
near IR to the far IR. An attacker with a IR illumination system (such
as in night-vison or FLIR systems, etc.) can illuminate in a chosen
spectral range with a power level much higher in his chosen band than
any reasonable bulb will put out. Moreover, he could of course
modulate (e.g.. chop) the illumination and lock-on only to the
modulated signal. In other words, the attacker has the choice of
wavelength and signal modulation to increase his S/N.

Still not likely, except for determined attackers and targets of high
economic or strategic value. I suspect the Waco compound was under IR
and microwave surveillance, for example. I suspect I am not, and in
any case, I don't worry about it.

(The real danger is not individual targetted surveillance, but
widespread and easy surveillance of communications and tracking of
locations, purchases, habits, etc.)

> > More importantly: attach a contact-speaker to each pane of glass, and feed
> > Top 40 radio to it. There have been reported cases of spy types bouncing
> > laser beams off windows and using the reflected beams to reproduce the
> > vibrations produced in the glass by reflected sound; in other words, the
> > window panes are large membranes which vibrate in sync with the sound that
> > hits them, so you want to override those vibrations with something else.
> 
> Won't work.  You need a random, independant source of noise.  Each
> window pane should have its own noise source attached to a speaker.
> If the speaker is tuned into a radio station, they too can tune into
> the same station, then substract the two signals giving them a fairly
> clear ear to listen in from.  A random noise source that is independant
> will do well because they can't substract it out.  If two windows in
> two different rooms also use the same random noise, they can differentiate
> between the two rooms and get the sound.

Still won't work well against determined attackers. The entropy of
English speech and the _localization_ of the speaker means several
things:

- multiple windows (or other vibrating conductors, if microwaves are
used) will have a correlated signal corresponding to the speaker,
whereas the added noise will be uncorrelated (generally...one can
imagine clever hacks to try to spoof the listeners by injecting some
correlation into the noise, but this is also detectable....you see the
point, I hope)

- speech models allow phonemes, words, etc., to be plucked out of even
noisy environments (we do it all the time....so do folks listening for
the characteristic signatures of submarines, etc.)

...

> In that case they'll probably resort to using microwaves to bounce off
> a metal item in the room which would also vibrate with any sounds in the
> room.  The only real defense against that would be strong shielding
> and a microwave detector to see if the shielding failed... the shielding
> has to be sound isolated or else the walls of the shielding could be
> used to get sound.. :-(  Pretty nasty shit, eh?

Which is why we'll eventually all plan our conspiracies with
non-speech, non-in-person methods, such as with secure telecom....

Wait! Do you think that's what Clipper and Digital Telephony are all about?

--Tim May

-- 
..........................................................................
Timothy C. May         | Crypto Anarchy: encryption, digital money,  
tcmay@netcom.com       | anonymous networks, digital pseudonyms, zero
408-688-5409           | knowledge, reputations, information markets, 
W.A.S.T.E.: Aptos, CA  | black markets, collapse of governments.
Higher Power: 2^859433 | Public Key: PGP and MailSafe available.
"National borders are just speed bumps on the information superhighway."

With FLIR you have SLIR  OTH UV  LOW LIGHT  from the military (Billy boy
is itching to deploy here in the good ole USA). Remote Sensing RADAR SONAR
Stealth RADAr, Remote Imaging SYStems all kinds of goodies coming home.
TO do what..fight crime..Yeah right. I remember law and order Nixon.
  Cryptography is the least of your problems. A high tech military is
coming home and Billy wants to put them to use on our streets..>!!!
He just loves gadgets. Dissent may become passse' in America.
 Wayne
****************************************************************************
*  Qjones@infi.net               So I'm a dog...what else is new?          *
*  Qjones@larry.wyvern.com        Quote from life and times of a man        *
****************************************************************************

Wayne Q Jones says:
> With FLIR you have SLIR  OTH UV  LOW LIGHT  from the military (Billy boy
> is itching to deploy here in the good ole USA). Remote Sensing RADAR SONAR
> Stealth RADAr, Remote Imaging SYStems all kinds of goodies coming home.
> TO do what..fight crime..Yeah right. I remember law and order Nixon.
>   Cryptography is the least of your problems. A high tech military is
> coming home and Billy wants to put them to use on our streets..>!!!
> He just loves gadgets. Dissent may become passse' in America.
>  Wayne

Now Wayne, you remember what the doctor said about you neededing to
take your medication EVERY DAY, don't you? Go back to the medicine
cabinet and take your medicine or they might send you back to the
hospital again and give you more shock therapy.

Perry

| Nope, it's da truth. :-)  I'm not doing this out of paranoia.  I'm
| learning about this incase the police state comes anytime soon.  It's
| far better to learn about it before than after it's too late. 

	When the police state arrives, doing any of the thigns
mentioned here will be cause for arrest.  If you didn't have anything
to hide, you'd be cooperating with the police, and writing all your
mail on post cards.

	If you want to hide, build deep underground, preferably in
hard, mineral bearing rock, like the bottom of a mine shaft.  Most of
the means of survelience in use rely on thin walls, windows, or easy
access for black bagging.  Of course, make sure you have plenty of
food and water, and multiple lines of communication out.  Also, old
mine shafts have been known to collapse when the BATF is around.

	Fighting a police state is much easier before it arrives.

Adam

-- 
Adam Shostack 				       adam@bwh.harvard.edu

Politics.  From the greek "poly," meaning many, and ticks, a small,
annoying bloodsucker.