We give a new algorithm for constructing Picard curves over a finite field with a given
endomorphism ring. This has important applications in cryptography since curves of
genus 3 allow one to work over smaller fields than the elliptic curve case. For a sextic
CM-field
containing the cube roots of unity, we define and compute certain class polynomials
modulo small primes and then use the Chinese remainder theorem to construct the
class polynomials over the rationals. We also give some examples.
Keywords
Picard curves, Chinese remainder theorem, number theory,
arithmetic geometry, constructing curves, genus 3