## Cryptology ePrint Archive: Report 2004/323

A note on López-Dahab coordinates

Tanja Lange

Abstract: López-Dahab coordinates are usually the system of choice for implementations of elliptic curves over binary fields. We give new formulas for doubling which need one squaring less and one more addition. This leads to a speed-up for binary fields in polynomial basis representation.

Category / Keywords: public-key cryptography / elliptic curves, coordinate system, fast implementation

Publication Info: To appear in proceedings of Wartacryp 2004, Tatra Mt. Math. Publ. 35

Date: received 24 Nov 2004, last revised 20 Jul 2006

Contact author: tanja at hyperelliptic org

Available format(s): Postscript (PS) | Compressed Postscript (PS.GZ) | PDF | BibTeX Citation

Note: Thanks to Mike Scott for pointing out a typo in the mixed addition.

Short URL: ia.cr/2004/323

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