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Thanks for your help. But FredericsC solutions is much more practical :)

Hey. Thanks. I just need to reverse the list because the highest coefficient is the first item in my list. Thanks ;)

Hi there,

Currently i'm trying to convert a list of coefficients automatically to a polynom. I got a list of zeros and ones and want to transform this list to a polynom in GF(2^8). First I set up the GF(2^8) with the reduction polynom

P2.<x> = GF(2)[];
p = x^8 + x^4 + x^3 + x + 1;
GF256 = GF(2^8, 'x', modulus=p)

Next I get a list of coefficients:

coeff = [0, 1, 0, 1, 1, 1, 0, 1]

which should be the polynom:

x^6 + x^4 + x^3 + x^2 + 1

How do I get this transformation from list to polynom automatically? The native thing I think about is I set up a string and fill in the coeff. like this:

polyString = str(coeff[7])+'*x^7 + '+str(coeff[6])...

And then cast it in GF256

poly = GF256(polyString)

But I think they are smarter ways out there.. Any ideas ? :)

Thanks. I used yours and @kcrisman's advice and went for a PolynomialRing! Cheers!

Hi Guys,

I got a symbolic expression in sage that looks like this:

2*s_0_0 + s_0_4 + 3

Can i somehow calculate this modulo 2? So the output would be:

s_0_4 + 1

Any ideas? :) Cheers!