🚀 go-pugleaf

In article <OTTO.89Oct17163149@tukki.jyu.fi> otto@tukki.jyu.fi (Otto J. Makela)
writes:
>Preventation: does anyone know of cheap but reasonably reliable scramblers ?

Ahhh -- I won't insist that those are mutually exclusive, but....

Cheap and easy to defeat -- sure. There was one in last year's Electronic Ex-
perimenters' Handbook (Popular Electronics). It's a simple double-balanced
modulator used to invert your voice signal. It's cheap. It's easy to build.
It's easy to defeat.

Expensive and hard to defeat -- sure, again. There are several manufacturers
in the business. A really good one digitizes the voice and performs an en-
cryption/decryption in the digital domain. Very, very hard to defeat. Very,
very hard to afford without corporate or government funding.

Expensive and easy to defeat -- probably. I've heard (that's rumor mill
level, so I don't take it too seriously) that some outfits make dippy
double-balanced modulators and sell 'em to the marks for kilobucks, then
run like hell. I don't know anything about it from personal experience, but
still, there are a lot of goniffs in this sort of business.

Cheap and hard to defeat -- I don't think it exists, but it could, and the
technology is HERE TODAY! It actually wouldn't be hard to integrate the whole
schmeer, including D/A, A/D, key management, (en/de)cryption, and an automatic
slicer-dicer for carrots all on the same chip. The thing that would make it
cheap is volume production, which probably won't happen, at least not soon.

Various Government Agencies (read: Big Brother) don't want powerful crypto-
graphic technology to get into the hands of T.C. Mits (and, really, I don't
blame them) since it would make their job much, much more difficult. The
technology is currently there for very secure voice "scrambling", but it
is still a mucho bucks proposition. The VGAs can live with this; there just
aren't very many of their ENEMIES who have the finances to play with this
stuff on any significant scale. Those who do -- the drug "wholesalers", the
Mafia and other organized crime, etc. -- are a minority who can be bugged
in other ways.

What most people don't realize (and I'm sure the VGAs do, but don't like to
publicize it -- for obvious reasons) is that anyone with a computer has a
very powerful cryptographic device at his disposal. It's not up to doing
real-time voice encryption (you need customized & dedicated hardware for that),
but if you don't mind communicating in blocks (write a letter, encrypt it, call
up your friend, enmodem the message, etc.), it'll work just fine. Use reason-
ably sophisticated algorithms, and none of the VGAs will be able to
cryptanalyze your stuff effectively. They MAY crack it with other techniques,
such as "practical cryptanalysis" -- stealing the key. Physical security is
another problem altogether, one you can't ignore. But that, as the textbooks
say, is beyond the scope of this discussion.

I'm tired; good night.

					Hope it helps,
						d


          "In all levels of life, the sheep are only safe
                  when the wolves are not hungry." -- F.J. Lovret
     Duke McMullan n5gax nss13429r phon505-255-4642 ee5391aa@hydra.unm.edu