## CryptoDB

### Paper: Suitable Curves for Genus-4 HCC over Prime Fields: Point Counting Formulae for Hyperelliptic Curves of type $y^2=x^{2k+1}+ax$

Authors: Mitsuhiro Haneda Mitsuru Kawazoe Tetsuya Takahashi URL: http://eprint.iacr.org/2004/151 Search ePrint Search Google Computing the order of the Jacobian group of a hyperelliptic curve over a finite field is very important to construct a hyperelliptic curve cryptosystem (HCC), because to construct secure HCC, we need Jacobian groups of order in the form $l(J\(Bcdot c$ where $l$ is a prime greater than about $2^{160}$ and $c$ is a very small integer. But even in the case of genus two, known algorithms to compute the order of a Jacobian group for a general curve need a very long running time over a large prime field. In the case of genus three, only a few examples of suitable curves for HCC are known. In the case of genus four, no example has been known over a large prime field. In this article, we give explicit formulae of the order of Jacobian groups for hyperelliptic curves over a finite prime field of type $y^2=x^{2k+1}+a x$, which allows us to search suitable curves for HCC. By using these formulae, we can find many suitable curves for genus-4 HCC and show some examples.
##### BibTeX
@misc{eprint-2004-12123,
title={Suitable Curves for Genus-4 HCC over Prime Fields: Point Counting Formulae for Hyperelliptic Curves of type $y^2=x^{2k+1}+ax$},
booktitle={IACR Eprint archive},
keywords={public-key cryptography / hyperelliptic curve cryptosystem, number theory},
url={http://eprint.iacr.org/2004/151},
note={ kawazoe@mi.cias.osakafu-u.ac.jp 12615 received 1 Jul 2004, last revised 15 Jul 2004},
author={Mitsuhiro Haneda and Mitsuru Kawazoe and Tetsuya Takahashi},
year=2004
}