In response to Harvey Newstrom:
It is a code where I use a document (extropians-digestV6#269), and
arbitrarily choose the word Dejanews in your message as the starting point.
I counted all the characters till I found an occurrence of the first letter
of my intended message - this is the first number in my message. Then again
I counted characters until the second letter of my message occurred, and so
forth. If I use the document only once, you cannot use any statistical
method to find the letters. You have to know at least the document I am
using, then with much trial and error you might find the arbitrary starting
point and decode the message.
Now, suppose you used the brute force approach of searching everything on
the net and trying which one fits - this message was too short to decode
with certainty - you would find thousands of documents yielding reasonable
and totally irrelevant decryptions. So you might stumble on the right one
but you wouldn't know it and you couldn't claim your million dollars if you
had a whole zip disk full of possible meaning for my message. If I wanted
to send a longer message, such that it would be unlikely to produce random
but meaningful decryptions, I would of course never use a codebook available
to to potential eavesdroppers - I would personally deliver a CD-ROM full of
digitized pictures form my wedding to the intended recipients and in that
case neither statistics, nor brute-force net search would help you. There
would be enough data on the disk for a few centuries of uncrackable email.
Talking about brute force - as Robert Coyyote remarked, rubber hose
decryption might be what it takes to crack this kind of scheme.
Are you game for a $ 1000000 challenge?
Rafal Smigrodzki, MD-PhD
smigrodzkir@msx.upmc.edu
This archive was generated by hypermail 2b30 : Sat May 11 2002 - 17:44:11 MDT