Inversion
Inversion of elements can be accomplished in many ways, including:
- Lookup tables — once again, only for small fields otherwise the table is too large for implementation
- Subfield inversion — by solving systems of equations in subfields
- Repeated square and multiply — for example in GF(2m), A−1 = A2m − 2
- The Extended Euclidean algorithm
- The Itoh-Tsujii inversion algorithm
Read more about this topic: Polynomial Basis