Note on the Ideal Exponentiation in Imaginary Quadratic Number and Function Fields

Abstract

By using a new formula of cubing ideals in imaginary quadratic number and function fields combined with Shank's NUCOMP algorithm, Imbert et al. presented a fast algorithms that compute a reduced output of cubing ideals and keep the sizes of the intermediate operands small. The authors asked whether there are specialized formulas to compute higher powers of ideals. In this note, we will derive such formulas.