

Abstract Algebra for developers - Cryptography - dhaivatpandya
http://poincare101.blogspot.com/2012/01/hi-hopefully-you-read-last-post-and-if.html

======
dmarquis
The difficulty of the discrete log problem doesn't have anything to do with
the modulus being prime, DLP is at least as hard for composite moduli. Its
considered a hard problem because after 30 years a fast algorithm hasn't been
found and a majority of experts think there isn't one. Also, a prime modulus
is used for Diffie Hellman since the set {1,2...,p-1} mod p forms a cyclic
group (under multiplication) which makes the method as simple as possible.
However, a slightly more complicated variation of DH could be used for a
composite modulus (where the group is not usually cyclic).

~~~
dhaivatpandya
If the modulus isn't prime, we can split it apart into two, much simpler
modular equations, which is part of the reason WHY its so hard to come up with
a good algorithm, and the other half is what you said.

------
dhaivatpandya
no comments? :(

~~~
simcop2387
It's a bit of a "holiday" in lots of places in the west. I imagine there's
lots of people that aren't bothering with the internet right now.

~~~
dhaivatpandya
Yeah, that's true. :)

------
aiscott
Complementary to this article is a book on Abstract Algebra that is released
under the GNU Free Document license.

<http://abstract.ups.edu/download/aata-original.pdf>

~~~
dhaivatpandya
I really like that book.

Its not where I first learned abstract algebra, but, its an excellent
resource.

