What is the addition rule for when the field is GF(2^m)?
In this case the addition rule has the form (x1,y1) + (x2,y2) = (x3,y3) where x3 = L^2 + L + x1 + x2 + a y3 = L·(x1+x3) + x3 + y1 L = (y1+y2)/(x1+x2) If x1=x2 and y1=y2 we must use instead x3 = L^2 + L + a y3 = x1^2 + (L+1)·x3 L = x1 + y1/x1 Again, there are some other special cases which must be considered first: if x1=x2 and y2=x1+y1 then the result is zero, and if either point is zero, the result is the other operand.
