From: mikebo@timesink.chi.il.us (Michael Borowiec)
Subject: Re: 800MHz Trunked Radio System Signals
Organization: HAM Radio Station N9EUZ, Naperville, IL
Date: Fri, 1 Jan 1993 22:57:59 GMT

In article <1992Dec30.155713.13188@anasazi.com> john@anasazi.com writes:
>Keywords: 
>
>In article <1992Dec30.061944.7061@timesink.chi.il.us> mikebo@timesink.chi.il.us (Michael Borowiec) writes:
>]In article <1992Dec29.180128.21441@anasazi.com> john@anasazi.com writes:
>]>In article <92360.134725PJB113@psuvm.psu.edu> me <PJB113@psuvm.psu.edu> writes:
>]>  (2) It is illegal to receive digitally encrypted signals. I don't know
>]>      if it is illegal to build decryptors, but if it isn't, it would be
>]>      quickly.
>]
>]I don't think you can outlaw a thing... only the illegal use of a thing.
>]There are exceptions however, such as drugs and dangerous weapons. I don't
>Sorry, but you can indeed outlaw a thing. The Electronic Communications
>Privacy Act of 1986 specifically OUTLAWS receiving encrypted signals
>unless you are the intended recipient. This is the same (ill conceived)
>law that outlaws receiving cell phone calls but leaves it legal to
>receive cordless phone calls. Go figure...

You are mistating yourself. I said you couldn't outlaw a "THING"
(object), only the USE of that "THING" (object). You said I was
wrong, and then proceeded to validate what I said... the law outlaws
the ACT of intentional reception of encrypted signals. Note that the
mere possession of the such receiving equipment is NOT ILLEGAL. It's
been my observation that only very few things (objects) are illegal
to possess, such as drugs and dangerous weapons.

For example, it is illegal to receive scrambled cable broadcasts
without paying for them - an ACTION. It is NOT ILLEGAL to possess a
descrambler box (THING/OBJECT) or to sell one, kit or not, unless you
are selling them for the express purpose of illegal reception.

>Yes, DES is relatively secure. However, the most recent cryptography research
>that I have read about claims that they believe DES is about as secure as is
>possible with a 56 bit key. That means you need an exhaustive key search
>(2^56 keys). At 100 Mips, you could figure maybe 100,000 tries per second?
>That would yield 548 YEARS of decryption time. Now, it is ALLEGED that the
>NSA eats DES messages for lunch, but I would point out that 20 million dollars
>for a specialized computer is peanuts to the NSA. I doubt they eat them
>for lunch with a few 100 MIPS computers!
>
Where do you get this $20M number from, out of thin air?

Have you seen the latest "Crack" program? As the system admin, I was
interested in how secure password encryption was. I ran "Crack" on my
password file and it busted over 60% of the DES encrypted passwords
on my systems within a week on a mere 33Mhz 386. These were not all
dictionary words either. Sure, this is a super easy example... but
the same techniques can be used to crack any encrypted plaintext.

>By the way, it is even more secure with voice encryption, because once you
>have it decoded, how can you tell that you have the right plaintext? More
>processing required. Most text info, on the other hand, is easier (letter
>frequency tests, parity bit tests, etc).
>
Yup... I'm sure audio complicates things. But I don't believe in
unsinkable ships or unbreakable codes. Never say never...  DVP presents
some neat challenges. I have no doubt the NSA is already able to crack
any system on the market. Much harder would be putting together spread
spectrum with a shifting hop pattern.
- Mike

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Michael Borowiec  (N9EUZ)  -  mikebo@timesink.chi.il.us  -  mikebo@isc.com
  >>> Dedicated to the Pursuit of Computer Assisted Time Dissipation <<<
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