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Re: encryption



I wrote an xpl encryption program once; I don't have it any more, but the
principle was this (I don't pretend to be sophisticated about this; this was
just my own clumsy way):
the encryption was based upon two things: an equation involving some
complexity, and a number key at least 4 digits long (a constant that had to
be plugged into the equation to make it work). Only a correspondent who had
both the equation and the key would be able, by normal means, to decode it.
The key, of course, could change. The equation was designed to accomplish
two purposes: substitute nonsense letters for real letters on a progressive
basis (so that, for example, k might stand for f the first time k was
included, but k would stand for nothing the second time, and then k would
stand for b the third time, etc.); and generate additional letters that had
no meaning - did not correspond to the real message - that were mixed in to
the string of code. These two features make it very difficult to break by
simple trial-and-error substitution, which is what computers are very good
at.
I wish I knew what happened to all my old xpl programs; I'm a bit daunted,
now that I have four children and a career, at trying to recreate most of
them, remembering how many hours it took me to write them.

Charles

----- Original Message -----
From: Morris Krok 
To: 
Sent: Saturday, September 22, 2001 3:20 PM
Subject: encryption


> from Morris,
>
>           From programmers point of view, using XPL how would
one
> go about encrypting a file. Am I right in saying that an easy method is by
> including it as part of a small program. Of course you have to know the
name
> of the program and an outsider not knowing how to assign such a program to
a
> key, will be unable to access the file. I am aware this is a somewhat
> primitive and crude way to a hide text from pyring eyes.
>
>   Strange but true I cannot seem to find the word "encryption" or
anything
> like it in a UK dictionary. Does this indicate that the British are not
just
> with it.