schnorr

Documentation

Overview

Package schnorr implements the vanilla Schnorr signature scheme. See https://en.wikipedia.org/wiki/Schnorr_signature.

The only difference regarding the vanilla reference is the computation of the response. This implementation adds the random component with the challenge times private key while the Wikipedia article substracts them.

The resulting signature is compatible with EdDSA verification algorithm when using the edwards25519 group, and by extension the CoSi verification algorithm.

Index

• func Sign(s Suite, private kyber.Scalar, msg []byte) ([]byte, error)
• func Verify(g kyber.Group, public kyber.Point, msg, sig []byte) error
• func VerifyWithChecks(g kyber.Group, pub, msg, sig []byte) error
• type Suite

Functions

func Sign

func Sign(s Suite, private kyber.Scalar, msg []byte) ([]byte, error)

Sign creates a Sign signature from a msg and a private key. This signature can be verified with VerifySchnorr. It's also a valid EdDSA signature when using the edwards25519 Group.

func Verify

func Verify(g kyber.Group, public kyber.Point, msg, sig []byte) error

Verify verifies a given Schnorr signature. It returns nil iff the given signature is valid.

func VerifyWithChecks

func VerifyWithChecks(g kyber.Group, pub, msg, sig []byte) error

VerifyWithChecks uses a public key buffer, a message and a signature. It will return nil if sig is a valid signature for msg created by key public, or an error otherwise. Compared to `Verify`, it performs additional checks around the canonicality and ensures the public key does not have a small order when using `edwards25519` group.

Types

type Suite

type Suite interface {
	kyber.Group
	kyber.Random
}

Suite represents the set of functionalities needed by the package schnorr.