statechain

README

Statechains

Statechains is an idea originally proposed by Ruben Somsen. He does a great job of explaining it in his bitcoin-dev post and in his medium article. This is a library in golang with the helper functions needed to support statechains.

References:

1. https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2019-June/017005.html
2. https://github.com/RubenSomsen/rubensomsen.github.io/blob/master/img/statechains.pdf
3. http://diyhpl.us/wiki/transcripts/building-on-bitcoin/2018/blind-signatures-and-scriptless-scripts/
4. http://diyhpl.us/wiki/transcripts/layer2-summit/2018/scriptless-scripts/
5. https://blockstream.com/2018/01/23/en-musig-key-aggregation-schnorr-signatures/
6. https://joinmarket.me/blog/blog/flipping-the-scriptless-script-on-schnorr/#rating-8
7. https://diyhpl.us/wiki/transcripts/scalingbitcoin/milan/schnorr-signatures/

Documentation

Index

• Variables
• func BlindClientBlind(Rx *big.Int, Ry *big.Int, m []byte, Px, Py *big.Int) (*big.Int, *big.Int, *big.Int, *big.Int, *big.Int, *big.Int)
• func BlindClientUnblind(alpha *big.Int, sig *big.Int) *big.Int
• func BlindServerNonce() (*big.Int, *big.Int, *big.Int)
• func BlindServerSign(k *big.Int, c *big.Int, privkey *big.Int) *big.Int
• func BytesToNum(byteString []byte) *big.Int
• func Construct22SchnorrPubkey(a, Ax, Ay, b, Bx, By *big.Int) (*big.Int, *big.Int, *big.Int, *big.Int, *big.Int, *big.Int, *big.Int, *big.Int)
• func ConstructAdaptorSig(x, Px, Py *big.Int, m []byte) (*big.Int, *big.Int, *big.Int, *big.Int, *big.Int, *big.Int, *big.Int)
• func Generate22AdaptorSchnorrChallenge(Jx, Jy, Rax, Ray, Rbx, Rby, Tx, Ty *big.Int, m []byte) *big.Int
• func Generate22SchnorrChallenge(Jx, Jy, Rax, Ray, Rbx, Rby *big.Int, m []byte) *big.Int
• func GetNewKeys() (*big.Int, *big.Int, *big.Int, error)
• func GetRandomness() *big.Int
• func InitStorage()
• func MuSig2CreateSign(x1, X1x, X1y, x2, X2x, X2y, r1, R1x, R1y, r2, R2x, R2y *big.Int, m []byte) (*big.Int, *big.Int, *big.Int, *big.Int, *big.Int)
• func MuSig2Verify(Rx, Ry, Xx, Xy, s *big.Int, m []byte) bool
• func NewPrivateKey() (*big.Int, error)
• func PubkeyPointsFromPrivkey(privkey *big.Int) (*big.Int, *big.Int)
• func SchnorrSign(k, Px, Py *big.Int, m []byte, privkey *big.Int) (*big.Int, *big.Int, *big.Int)
• func SchnorrVerify(sig *big.Int, Rx, Ry *big.Int, Px, Py *big.Int, m []byte) bool
• func SerializeCompressed(pkx *big.Int, pky *big.Int) []byte
• func StateServerRequestNewPubkey(userPubkey []byte) (*big.Int, *big.Int, error)
• func StatechainGenMuSigKey(X1x, X1y, X2x, X2y *big.Int) ([]byte, *big.Int, *big.Int)
• func StatechainRequestBlindSig(userSig *big.Int, blindedMsg *big.Int, k *big.Int, userPubkey []byte, ...) (*big.Int, error)
• func VerifyAdaptorSig(spr, Rx, Ry, Tx, Ty, Px, Py *big.Int, m []byte) bool

Variables

var Curve *btcec.KoblitzCurve = btcec.S256() // take only the curve, can't use other stuff

var Storage map[string][]*big.Int

Functions

func BlindClientBlind

func BlindClientBlind(Rx *big.Int, Ry *big.Int, m []byte, Px, Py *big.Int) (
	*big.Int, *big.Int, *big.Int, *big.Int, *big.Int, *big.Int)

func BlindClientUnblind

func BlindClientUnblind(alpha *big.Int, sig *big.Int) *big.Int

func BlindServerNonce

func BlindServerNonce() (*big.Int, *big.Int, *big.Int)

func BlindServerSign

func BlindServerSign(k *big.Int, c *big.Int, privkey *big.Int) *big.Int

func BytesToNum

func BytesToNum(byteString []byte) *big.Int

func Construct22SchnorrPubkey

func Construct22SchnorrPubkey(a, Ax, Ay, b, Bx, By *big.Int) (*big.Int, *big.Int, *big.Int, *big.Int,
	*big.Int, *big.Int, *big.Int, *big.Int)

func ConstructAdaptorSig

func ConstructAdaptorSig(x, Px, Py *big.Int, m []byte) (*big.Int,
	*big.Int, *big.Int, *big.Int, *big.Int, *big.Int, *big.Int)

func Generate22AdaptorSchnorrChallenge

func Generate22AdaptorSchnorrChallenge(Jx, Jy, Rax, Ray, Rbx, Rby, Tx, Ty *big.Int, m []byte) *big.Int

func Generate22SchnorrChallenge

func Generate22SchnorrChallenge(Jx, Jy, Rax, Ray, Rbx, Rby *big.Int, m []byte) *big.Int

func GetNewKeys

func GetNewKeys() (*big.Int, *big.Int, *big.Int, error)

func GetRandomness

func GetRandomness() *big.Int

func InitStorage

func InitStorage()

func MuSig2CreateSign

func MuSig2CreateSign(x1, X1x, X1y, x2, X2x, X2y, r1, R1x, R1y, r2, R2x, R2y *big.Int,
	m []byte) (*big.Int, *big.Int, *big.Int, *big.Int, *big.Int)

func MuSig2Verify

func MuSig2Verify(Rx, Ry, Xx, Xy, s *big.Int, m []byte) bool

func NewPrivateKey

func NewPrivateKey() (*big.Int, error)

func PubkeyPointsFromPrivkey

func PubkeyPointsFromPrivkey(privkey *big.Int) (*big.Int, *big.Int)

func SchnorrSign

func SchnorrSign(k, Px, Py *big.Int, m []byte, privkey *big.Int) (*big.Int, *big.Int, *big.Int)

func SchnorrVerify

func SchnorrVerify(sig *big.Int, Rx, Ry *big.Int, Px, Py *big.Int, m []byte) bool

func SerializeCompressed

func SerializeCompressed(pkx *big.Int, pky *big.Int) []byte

SerializeCompressed serializes a public key in a 33-byte compressed format.

func StateServerRequestNewPubkey

func StateServerRequestNewPubkey(userPubkey []byte) (*big.Int, *big.Int, error)

func StatechainGenMuSigKey

func StatechainGenMuSigKey(X1x, X1y, X2x, X2y *big.Int) ([]byte, *big.Int, *big.Int)

func StatechainRequestBlindSig

func StatechainRequestBlindSig(userSig *big.Int, blindedMsg *big.Int, k *big.Int,
	userPubkey []byte, Bx, By *big.Int, nextUserPubkey []byte) (*big.Int, error)

func VerifyAdaptorSig

func VerifyAdaptorSig(spr, Rx, Ry, Tx, Ty, Px, Py *big.Int, m []byte) bool