EdDSA for more curves
DJ Daniel Bernstein, Simon Josefsson, Tanja Lange, Peter Schwabe, BY Yang · IACR Cryptology ePrint Archive · 2015
The original specification of EdDSA was suitable only for finite fields Fq with q mod 4 = 1. The main purpose of this document is to extend EdDSA to allow finite fields Fq with any odd q. This document also extends EdDSA to support prehashing, i.e., signing the hash of a message. Keywords: Signatures, elliptic curves, Edwards curves, Ed25519, Curve41417, Ed448-Goldilocks, Ed521