Where is Abastract Algebra and Number Theory in Computer Science?

MathWarrior

I was wondering if someone can describe a few concrete examples of where abstract algebra alone pops up in computer science? The only area I have found is cryptography, is their other areas?

I was also wondering if someone can describe some concrete examples of where number theory comes to light in computer science. Once again the only area I have found is cryptography, are their other areas?


Thanks