bls

Documentation

Overview

Package bls implements the Boneh-Lynn-Shacham (BLS) signature scheme which was introduced in the paper "Short Signatures from the Weil Pairing". BLS requires pairing-based cryptography.

Index

• func AggregatePublicKeys(suite pairing.Suite, Xs ...kyber.Point) kyber.Point
• func AggregateSignatures(suite pairing.Suite, sigs ...[]byte) ([]byte, error)
• func NewKeyPair(suite pairing.Suite, random cipher.Stream) (kyber.Scalar, kyber.Point)
• func Sign(suite pairing.Suite, x kyber.Scalar, msg []byte) ([]byte, error)
• func Verify(suite pairing.Suite, X kyber.Point, msg, sig []byte) error

Functions

func AggregatePublicKeys

func AggregatePublicKeys(suite pairing.Suite, Xs ...kyber.Point) kyber.Point

AggregatePublicKeys takes a slice of public G2 points and returns the sum of those points. This is used to verify multisignatures.

func AggregateSignatures

func AggregateSignatures(suite pairing.Suite, sigs ...[]byte) ([]byte, error)

AggregateSignatures combines signatures created using the Sign function

func NewKeyPair

func NewKeyPair(suite pairing.Suite, random cipher.Stream) (kyber.Scalar, kyber.Point)

NewKeyPair creates a new BLS signing key pair. The private key x is a scalar and the public key X is a point on curve G2.

func Sign

func Sign(suite pairing.Suite, x kyber.Scalar, msg []byte) ([]byte, error)

Sign creates a BLS signature S = x * H(m) on a message m using the private key x. The signature S is a point on curve G1.

func Verify

func Verify(suite pairing.Suite, X kyber.Point, msg, sig []byte) error

Verify checks the given BLS signature S on the message m using the public key X by verifying that the equality e(H(m), X) == e(H(m), x*B2) == e(x*H(m), B2) == e(S, B2) holds where e is the pairing operation and B2 is the base point from curve G2.