EdDSA for more curves

Abstract

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