HDTenEightyP/NetNews huggingface dataset:
From: pcl@ox.ac.uk (Paul C Leyland)
Newsgroups: sci.crypt
Subject: Re: Any way to *CREATE* Vcr+ (VCR PLUS) codes??? (please read)
Date: 6 Jan 93 10:58:30 GMT
	<a_rubin.726253952@dn66> <1993Jan5.191138.16420@netcom.com>
Organization: Oxford University Computing Services, 13 Banbury Rd Oxford OX2
	6NN
In-reply-to: strnlght@netcom.com's message of 5 Jan 93 19:11:38 GMT

In article <1993Jan5.191138.16420@netcom.com> strnlght@netcom.com (David Sternlight) writes:

...

   Finally, there seem to be two sets of codes. One, of up to six digits,
   is for the standard start times (on the half-hour) and lengths (multiples
   of 30 minutes). A second, of more digits, seems to be for the exception
   cases. The first set has now been broken and a convenient pair of
   "c" routines is making its way around the world. The second has not
   yet been broken, as far as I can tell, but is mostly of interest only to
   make sure the recordings of cable movies with odd ending times are
   correctly stopped to avoid wasting tape.

Of much greater interest on this side of the pond.  In the UK, TV
programs very often start and finish on non-30 minute boundaries.  I,
for one, would like to see a complete solution.

Paul
--
Paul Leyland <pcl@oxford.ac.uk>          | Hanging on in quiet desperation is
Oxford University Computing Service      |     the English way.
13 Banbury Road, Oxford, OX2 6NN, UK     | The time is come, the song is over.
Tel: +44-865-273200  Fax: +44-865-273275 | Thought I'd something more to say.
Finger pcl@black.ox.ac.uk for PGP key    |
Newsgroups: sci.crypt,alt.society.civil-liberty
From: gardner@convex.com (Steve Gardner)
Subject: Re: Question from someone who's new to all this
Date: Mon, 4 Jan 1993 16:57:14 GMT
Organization: Engineering, CONVEX Computer Corp., Richardson, Tx., USA
X-Disclaimer: This message was written by a user at CONVEX Computer
              Corp. The opinions expressed are those of the user and
              not necessarily those of CONVEX.

In article <1993Jan3.170453.28445@zip.eecs.umich.edu> positron@quip.eecs.umich.edu (Jonathan Haas) writes:
>How can someone (PKP) patent a mathematical algorithm?
>Has this patent yet been challenged in court? It seems
>to me that it would be like trying to patent the Pythagorean
>Theorem.
	It is my understanding that they can only patent an algorithm
	under the US view of "intellectual property".  The US has been
	trying to force this view on the rest of its trading partners
	for some time.  Fortunately with some lack of success.


						smg
Newsgroups: sci.crypt
From: rlglende@netcom.com (Robert Lewis Glendenning)
Subject: Compression and Randomization == Encryption
Organization: Netcom Online Communications Services (408-241-9760 login: guest)
Date: Thu, 7 Jan 1993 04:59:21 GMT

Yes, compression software provides clues just the same as standard headers.
However, compression also reduces redundancy.

I believe that Shannon's Information Theory implies that a signal with no
redundancy is uncrackable.  So, if you merely randomize the order of the
compressed bytes, the difficulty of cracking it should be an exponential
order of the length of the message.  If you want to make sure, and for short
messages, add some random stuff.  Then the cracker has the problem of separating
the signal from the noise, ordering it, and then (the easy part) decompressing
it.

I keep wondering why this appraoch isn't intellectually respectable.  At minor
computational cost and selectable increase in comm costs, it appears that
you can have a vast increase in security, including resistance to cracking
traffic beginning with common headers, etc.

I guess I am a novice also, because I don't appear to understand either.

Lew
-- 
Lew Glendenning		rlglende@netcom.com
"Perspective is worth 80 IQ points."	Nils Bohr (or somebody like that).
Newsgroups: sci.crypt
From: bontchev@fbihh.informatik.uni-hamburg.de (Vesselin Bontchev)
Subject: Re: Any way to *CREATE* Vcr+ (VCR PLUS) codes??? (please read)
Keywords: VCR+ patent
Reply-To: bontchev@fbihh.informatik.uni-hamburg.de
Organization: Virus Test Center, University of Hamburg
Date:  4 Jan 93 22:11:14 GMT

donovan@calvin.ee.udel.edu (Greg Donovan) writes:

> Look in alt.sources or rec.video.  There is a posting containing a shar
> of code to encode/decode numbers and times.  Here is the description 
> from the header:

> This ZIP archive holds three files
> X      readme.txt
> X      encode.c
> X      decode.c

Hmm... isn't there an ftp site that has them or could somebody post
them here for those of us who do not have access to the above
newsgroups? Thanks.

Regards,
Vesselin
-- 
Vesselin Vladimirov Bontchev          Virus Test Center, University of Hamburg
Tel.:+49-40-54715-224, Fax: +49-40-54715-226      Fachbereich Informatik - AGN
< PGP 2.1 public key available on request. > Vogt-Koelln-Strasse 30, rm. 107 C
e-mail: bontchev@fbihh.informatik.uni-hamburg.de    D-2000 Hamburg 54, Germany
From: karn@servo.qualcomm.com (Phil Karn)
Newsgroups: sci.crypt
Subject: Re: Motorola 'Secure-Clear' Cordless Telephones
Date: 4 Jan 93 22:03:03 GMT
Organization: Qualcomm, Inc

In article <ueuhkm0@sgi.sgi.com> rpw3@rigden.wpd.sgi.com (Rob Warnock) writes:
>2. If the FM "deviation" is large, there will be significant AM-like sidebands
>   that might be listened to with an SBB receiver with sufficiently narrow
>   filters. [O.k., my math's weak on this one. Maybe Phil Karn or some other
>   radio-knowledgable type could comment further on this case.]

Actually, it's if the FM deviation is *small*. At arbitrarily small
values of deviation, the FM signal closely resembles an AM signal
except that the sidebands are 90 degrees out of phase with the carrier
(instead of being in phase). However, this doesn't matter to a SSB
receiver since they ignore any transmitted carrier anyway.

However, the canonical way to "decode" frequency inverted speech is
with a "ring modulator". The "speech descrambling" kits you see in the
back of electronics magazines are nothing more than this: two audio
transformers, each with two windings, one center-tapped, four diodes
and an audio oscillator.  You wire the diodes as a ring (all four
diodes pointing the same way, NOT the same as a bridge rectifier).

Another way to decode frequency inversion is with DSP (digital signal
processing; NEXTstation users take note). You simply invert the sign
of every other input sample, and vary the sampling rate to vary the
inversion frequency.

Phil
Newsgroups: sci.crypt
From: etxjnor@solsta.ericsson.se (Jan Norden  TX/DK)
Subject: signatures
Organization: Ericsson
Date: Fri, 8 Jan 1993 10:31:11 GMT



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Newsgroups: sci.crypt
From: Owen.Lewis@purplet.demon.co.uk (Owen Lewis)