Re: Matrix-Multiplication: Security?

Anton wrote:
> I've written a Delphi-program to encode textmessages with
> matrix-multiplication.
[...]
> my teacher want to know the security especially compared with
> standards like DES etc.

Take heart Anton; all is not lost.
The answers have not been what you wanted to hear. They are
correct, but don't worry; lots of smart people have designed
insecure ciphers. In fact, quite a few have come up with the
matrix-multiplication cipher.

You can still produce an excellent computer-science class
project. Write up why you intuitively expected the cipher to be
secure, and then show how you found your expectation to be
false. Read the posts, in particular Peter Pearson's, and follow
through to break the cipher.

That's science: make a hypothesis, and then pursue the evidence
that would *disprove* it. A paper that shows how to break a
simple and appealing cipher is superior to one that proposes
some method and concludes "I don't know how to break it".

-- 
--Bryan