Let ϵ>0. In this article we will present a deterministic algorithm which does the following. The input is a hyperelliptic curve C of genus g over a finite field k of cardinality q given by y2+h(x)y=f(x) such that the x -coordinate map is ramified at ∞. In time O(g2+ϵq1/2+ϵ) the algorithm outputs a set of generators of the Picard group c3078dd71f995f255a">. This extends results which others have obtained when g=1.
In this article we introduce a combinatorial tool, the shape parameter, which we use together with character sum estimates from class field theory to deduce the statement.