Cryptology ePrint Archive: Report 2006/331

On the Security of Generalized Jacobian Cryptosystems

Isabelle Dechene

Abstract: Generalized Jacobians are natural candidates to use in discrete logarithm (DL) based cryptography since they include the multiplicative group of finite fields, algebraic tori, elliptic curves as well as all Jacobians of curves. This thus led to the study of the simplest nontrivial generalized Jacobians of an elliptic curve, for which an efficient group law algorithm was recently obtained. With these explicit equations at hand, it is now possible to concretely study the corresponding discrete logarithm problem (DLP); this is what we undertake in this paper. In short, our results highlight the close links between the DLP in these generalized Jacobians and the ones in the underlying elliptic curve and finite field.

Category / Keywords: Discrete logarithm problem, generalized Jacobians, semi-abelian varieties, elliptic curves, finite fields, pairing-friendly curves

Date: received 29 Sep 2006, last revised 24 Mar 2007

Contact author: idechene at uwaterloo ca

Available format(s): PDF | BibTeX Citation

Note: Improved version of the original submission, including updated references as well as a simpler proof of Proposition 3.

Version: 20070324:222846 (All versions of this report)

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