International Association for Cryptologic Research

International Association
for Cryptologic Research

IACR News item: 27 May 2013

Andres Enge, Emmanuel Thomé
ePrint Report ePrint Report
We describe a quasi-linear algorithm for computing Igusa class polynomials of Jacobians of genus 2 curves via complex floating-point approximations of their roots. After providing an explicit treatment of the computations in quartic CM fields and their Galois closures, we pursue an approach due to Dupont for evaluating ϑ-constants in quasi-linear time using Newton iterations on the Borchardt mean. We report on experiments with our implementation and present an example with class number 17608.

Expand

Additional news items may be found on the IACR news page.