# Number Theory 101

Disclaimer: I am *not* a mathematician. I just happened to take a Number Theory class from an awesome professor (Dr Blakley) at Texas A&M.

When I took Dr Blakley’s Math 673 class, I was in over my head at first (and probably still would be if I hadn’t seen the applications of the topics in his class since taking his class). Unfortunately, I graduated and didn’t get to take the second part of the course, which friends told me was just as good as the first part. We learned about polynomial math, and at the time, I had no clue what it could be used for…. Then a friend linked me to this awesome stick figure explanation of AES. Once again, I remembered seeing this “math” in Dr Blakley’s class. We did a lot more with it than the AES description shows (but I couldn’t tell you what or how).

We first learned finite field arithmetic by drawing the fields and looking up the solution on the “chart.” Then, we moved to making sure that we understood modulo arithmetic. Then, we finally learned how to apply this to polynomials. (I still didn’t get my aha! moment until years later). But, now, I can read (and understand) the stick figure description of AES. It’s worth learning if you want to delve deeper into cryptography, as many cryptographic functions are based on math learned in a number theory class.