Cryptography-Digest Digest #916, Volume #11 Fri, 2 Jun 00 02:13:01 EDT
Contents:
Re: Tableaus Revisited, Again (wtshaw)
Re: Tableaus Revisited, Again (wtshaw)
Re: Can we say addicted? (wtshaw)
Re: Is it possible to use encryption to solve this problem? (S. T. L.)
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From: [EMAIL PROTECTED] (wtshaw)
Subject: Re: Tableaus Revisited, Again
Date: Thu, 01 Jun 2000 21:34:17 -0600
In article <[EMAIL PROTECTED]>, Jim Gillogly <[EMAIL PROTECTED]> wrote:
> Mok-Kong Shen wrote:
> > I always wonder why Vigenere was that popular and people didn't
> > widely employ substitution tables with independent alphabets, i.e.
> > with each column being an arbitrary permutation of the alphabet.
> > Do you happen to know of a reason?
>
> The system Vigenere invented did use arbitrary permutations of the
> alphabet, unlike the system now known by his name. The Fuer GOD cipher
> used by the Germans in World War 1 was a polyalphabetic with unrelated
> alphabets. The Allies used a system called SYKO in WW2 with 30 or 32
> mixed alphabets. It was still far too insecure.
>
Such things are at the toy end of the cipher spectrum, but still
interesting to contemplate. A variety of means are used to up the ante
when solving is too easy, not much of a challenge, much less something to
put lives on.
--
If a privacy policy is longer that 250 words, it is already
deceptive; the longer the more deceptive.
------------------------------
From: [EMAIL PROTECTED] (wtshaw)
Subject: Re: Tableaus Revisited, Again
Date: Thu, 01 Jun 2000 21:29:44 -0600
In article <[EMAIL PROTECTED]>, Mok-Kong Shen
<[EMAIL PROTECTED]> wrote:
> wtshaw wrote:
>
> > The basis for all of cryptography stems from the same roots. Beaufort and
> > Vigenere are two systems with the same mission, such that their solutions
> > are almost the same. It's like approaching a mountain, and photographing
> > it from two different directions. The third complement is the Beaufort
> > Deviant, better known as the Deviant.
>
> I always wonder why Vigenere was that popular and people didn't
> widely employ substitution tables with independent alphabets, i.e.
> with each column being an arbitrary permutation of the alphabet.
> Do you happen to know of a reason?
>
> M. K. Shen
Actually there is no reason that the original vigenere's could not use
independent alphabets, as the edge alphabets were separate from the body.
--
If a privacy policy is longer that 250 words, it is already
deceptive; the longer the more deceptive.
------------------------------
From: [EMAIL PROTECTED] (wtshaw)
Subject: Re: Can we say addicted?
Date: Thu, 01 Jun 2000 21:46:12 -0600
In article <[EMAIL PROTECTED]>, tomstd
<[EMAIL PROTECTED]> wrote:
> Hehehe I finished my bio work for the week so I decided to make
> another cipher...
>
..
>
> I am so addicted to this....
>
You too? O, well, it's better than drugs, I suppose.
--
If a privacy policy is longer that 250 words, it is already
deceptive; the longer the more deceptive.
------------------------------
From: [EMAIL PROTECTED] (S. T. L.)
Subject: Re: Is it possible to use encryption to solve this problem?
Date: 02 Jun 2000 05:15:17 GMT
<<We want to have an application that users can buy.
We also can provide add-ons to the application.
We want to be able to sell these add-ons over the Internet via a
subscription service.
However, we want to make sure that one user doesn't simply pay for the
add-ons and then simply give them away to others, bypassing the
subscription service.>>
You can of course have a scheme that binds the plugins to specific copies of
software: have each copy of the software have a unique serial number embedded
somewhere deep in the application, and have each plugin have its own serial
number embedded somewhere deep, and have the software check both numbers to see
if they match. The problem is, if you have executable code on a system, a
determined hacker can and WILL (if he's determined enough) execute it, no
matter how many checks and comparisons and safeguards you put in the way. (He
could rip out the code that compares serial numbers and put in a dummy routine
that just tells the program "serial numbers match, go ahead", for example). As
others have said, you want to make this hard enough so that no one will bother,
but you do _not_ want to inconvenience your paying customers. Things involving
hidden files on the system really piss off real customers who do things like
upgrade computers or defragment hard drives. Arcane hardware dongles are even
more annoying. Copy protection is probably the last thing you should worry
about. Making good software should be the first thing.
-*---*-------
S.T.L. Quotes page: http://quote.cjb.net Now playing: Half-Life
"Never invest in something that violates a conservation law" - John Walker
"If anyone wants a hole in the ground, nuclear explosives can make big holes" -
Edward Teller
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