RE: Another Crypting System

Michael J Gebis (gebis@ecn.purdue.edu)
Fri, 18 Apr 1997 11:14:40 -0500 (EST)


Johan Hartzenberg (JohnanH@CCMA.org.za) writes:
>Would any of you be interested in looking at an Encryption system I
>pretty much wrote myself.

>I don't know much about crypting algorythms and I don't know how to
>calculate the time needed to brute force crack the algorythm. Also I
>don't know how to work out if it's crackable by something other than
>brute force. Maybe one of you can help me.

There really is no good point to inventing a new ciphersystem,
especially if you "don't know much about crypting algorythms". There
are existing systems out there that are strong and free (heck, DES
still ain't that bad, and if you wanted a few more years of security,
you could hack the key schedule to use 64 bits instead of 56)
It's far too easy to invent something that's "confusing" as opposed to
"strong".

I assume this is a learning exercise: you will learn more either
trying to break a known cipher system (vigenere or affine are two
pretty simply broken systems) than inventing your own. You will also
learn more implementing a known cipher system.

>Anyways, the other thing that weakens encryption schemes is the length
>of the data that was encrypted.

Why do you say this?

-- 
Mike Gebis  gebis@ecn.purdue.edu  mgebis@eternal.net