(blanket issue) add features found in libgf2

Hey, it looks like you’ve done a really thorough job here, at least at first glance.

I have a library, libgf2, which no one else actually uses, that has a couple of features that might be missing from the galois library, including:

• LFSR support including Berlekamp-Massey for finding the characteristic polynomial of an LFSR sequence
• quotient rings using specified polynomials
• discrete logarithm (in the easier cases)

Give it a look-see… I have zero time right now to help but maybe in a year or so my schedule will ease up and I can help contribute here.

[jason-s]

Hey, thanks for reaching out!

Well, I should thank you for your answer on StackOverflow to my question from 2013, otherwise I wouldn’t have found out about this project.

[jason-s]

Permission granted on copying anything from libgf2 as long as you give credit + a reference to it. (+ to Part 1 of my articles on LFSRs if you don’t mind) My name is Jason Sachs. I picked the Apache license for libgf2 but I’m open to granting permission for any permissive license; MIT is fine.

I’m curious how performance compares; I was able to get reasonable performance from Python via Cython for multiplication + modulo, but didn’t go any further. I’m very familiar with numba, haven’t tried to use it for this stuff yet so it’s exciting to see this.

There’s also a Java library jlibgf2 which isn’t as mature, but it does have a number of primitive polynomial generation methods implemented whereas libgf2 does not. (See Part XVIII)