question about finite fields,please help me!!!

["UMBERTO COVA" <umbercova@tiscalinet.it>]

First of all,thanks for your help!

I need to know how I can determine a generator of a finite field using Pari;is there a specific function that builds a primitive polynomial of degree n over a field Fp(something similar to ffinit)?

Futhermore,how can I realize a modular exponentiation of a polynomial (f(x))^a (mod g(x)) without problems of overflow and in a reasonable time?

 

Thank you very much

Umberto Cova