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The following archive was created by hippie-mail 7.98617-22 on Sat Apr 10 1999 - 01:15:23
Alex Alten (Alten@Home.Com)
Thu, 29 Oct 1998 22:14:01 -0800
At 08:58 AM 10/29/98 +0100, Mok-Kong Shen wrote:
>Alex Alten wrote:
>
>> The concept of swapping to get a random string of bits is very interesting.
>> >From what I understand when one shuffles a deck of 52 cards 7 or more
times
>> the card order becomes unpredictable e.g. random. The shuffle must be
>> what is called a "near perfect" shuffle. In other words the cards can't
>
>You are right. The quality of shuffling depends on the quality of
>the PRNG being used in the shuffling algorithm.
>
Taking this a step further. Say you had a security system where all messages
were exactly some fixed number of bytes, say 64 bytes each. Now the number
of possible combinations is 64!, which is somewhere around 2^296. This means
that if you could represent each unique shuffle pattern with a unique number
you would have a cryptosystem with keys of 296 bits each. However if the
messages are structured or subject to frequency analysis then I suspect that
the strength would be reduced quite a bit. In that case it's probably better
to use it to construct a message length random key to XOR against the clear
text. One could build practical variants that could be useful in such
a restricted message size environment (say a payment system with small
monetary messages).
Anyway it's a fun mental doodle if nothing else. Good night!
- Alex
--Alex Alten
Alten@Home.Com Alten@TriStrata.Com
P.O. Box 11406 Pleasanton, CA 94588 USA (925) 417-0159
The following archive was created by hippie-mail 7.98617-22 on Sat Apr 10 1999 - 01:15:23