International Association for Cryptologic Research

International Association
for Cryptologic Research

CryptoDB

Genus 2 Curves with Complex Multiplication

Authors:
Eyal Z. Goren
Kristin E. Lauter
Download:
URL: http://eprint.iacr.org/2010/156
Search ePrint
Search Google
Abstract: Genus 2 curves are useful in cryptography for both discrete-log based and pairing-based systems, but a method is required to compute genus 2 curves with Jacobian with a given number of points. Currently, all known methods involve constructing genus 2 curves with complex multiplication via computing their 3 Igusa class polynomials. These polynomials have rational coefficients and require extensive computation and precision to compute. Both the computation and the complexity analysis of these algorithms can be improved by a more precise understanding of the denominators of the coefficients of the polynomials. The main goal of this paper is to give a bound on the denominators of Igusa class polynomials of genus 2 curves with CM by a primitive quartic CM field $K$. We give an overview of Igusa's results on the moduli space of genus two curves and the method to construct genus 2 curves via their Igusa invariants. We also give a complete characterization of the reduction type of a CM abelian surface, for biquadratic, cyclic, and non-Galois quartic CM fields, and for any type of prime decomposition of the prime, including ramified primes.
BibTeX
@misc{eprint-2010-23057,
  title={Genus 2 Curves with Complex Multiplication},
  booktitle={IACR Eprint archive},
  keywords={public-key cryptography / Hyperelliptic Curve Cryptography, Number Theory},
  url={http://eprint.iacr.org/2010/156},
  note={none klauter@microsoft.com 14692 received 23 Mar 2010},
  author={Eyal Z. Goren and Kristin E. Lauter},
  year=2010
}