From bafc755bb2a855b807933d57d66820961a1dc433 Mon Sep 17 00:00:00 2001
From: Jakub Sztandera <oss@kubuxu.com>
Date: Mon, 15 Apr 2024 12:00:49 -0500
Subject: [PATCH] Switch to signatures on G2, Resolves #96

Signed-off-by: Jakub Sztandera <oss@kubuxu.com>
---
 blssig/aggregation.go | 7 +++----
 blssig/signer.go      | 6 +++---
 blssig/suite_test.go  | 4 ++--
 blssig/verifier.go    | 8 +++++---
 sim/sim.go            | 4 ++--
 5 files changed, 15 insertions(+), 14 deletions(-)

diff --git a/blssig/aggregation.go b/blssig/aggregation.go
index a2e60a09..09b390c1 100644
--- a/blssig/aggregation.go
+++ b/blssig/aggregation.go
@@ -7,7 +7,6 @@ import (
 
 	"github.com/drand/kyber"
 	"github.com/drand/kyber/sign"
-	"github.com/drand/kyber/sign/bdn"
 	"golang.org/x/xerrors"
 )
 
@@ -22,7 +21,7 @@ func (v Verifier) Aggregate(pubkeys []gpbft.PubKey, signatures [][]byte) ([]byte
 		return nil, xerrors.Errorf("converting public keys to mask: %w", err)
 	}
 
-	aggSigPoint, err := bdn.AggregateSignatures(v.suite, signatures, mask)
+	aggSigPoint, err := v.scheme.AggregateSignatures(signatures, mask)
 	if err != nil {
 		return nil, xerrors.Errorf("computing aggregate signature: %w", err)
 	}
@@ -40,12 +39,12 @@ func (v Verifier) VerifyAggregate(msg []byte, signature []byte, pubkeys []gpbft.
 		return xerrors.Errorf("converting public keys to mask: %w", err)
 	}
 
-	aggPubKey, err := bdn.AggregatePublicKeys(v.suite, mask)
+	aggPubKey, err := v.scheme.AggregatePublicKeys(mask)
 	if err != nil {
 		return xerrors.Errorf("aggregating public keys: %w", err)
 	}
 
-	return bdn.Verify(v.suite, aggPubKey, msg, signature)
+	return v.scheme.Verify(aggPubKey, msg, signature)
 }
 
 func (v Verifier) pubkeysToMask(pubkeys []gpbft.PubKey) (*sign.Mask, error) {
diff --git a/blssig/signer.go b/blssig/signer.go
index ac6b0a6d..0d5fedce 100644
--- a/blssig/signer.go
+++ b/blssig/signer.go
@@ -21,12 +21,12 @@ type Signer struct {
 	keys map[string]kyber.Scalar
 }
 
-func SignerWithKeyOnG2() *Signer {
+func SignerWithKeyOnG1() *Signer {
 	suite := bls12381.NewBLS12381Suite()
 	return &Signer{
 		suite:    suite,
-		scheme:   bls.NewSchemeOnG1(suite),
-		keyGroup: suite.G2(),
+		scheme:   bls.NewSchemeOnG2(suite),
+		keyGroup: suite.G1(),
 		keys:     make(map[string]kyber.Scalar),
 	}
 }
diff --git a/blssig/suite_test.go b/blssig/suite_test.go
index 049c8928..cf3bbb2d 100644
--- a/blssig/suite_test.go
+++ b/blssig/suite_test.go
@@ -9,6 +9,6 @@ import (
 
 func TestBLSSigning(t *testing.T) {
 	test.NewSigningSuite(
-		blssig.SignerWithKeyOnG2(),
-		blssig.VerifierWithKeyOnG2()).Run(t)
+		blssig.SignerWithKeyOnG1(),
+		blssig.VerifierWithKeyOnG1()).Run(t)
 }
diff --git a/blssig/verifier.go b/blssig/verifier.go
index 46b58fc5..f274e3ac 100644
--- a/blssig/verifier.go
+++ b/blssig/verifier.go
@@ -11,14 +11,16 @@ import (
 
 type Verifier struct {
 	suite    pairing.Suite
+	scheme   *bdn.Scheme
 	keyGroup kyber.Group
 }
 
-func VerifierWithKeyOnG2() Verifier {
+func VerifierWithKeyOnG1() Verifier {
 	suite := bls12381.NewBLS12381Suite()
 	return Verifier{
 		suite:    suite,
-		keyGroup: suite.G2(),
+		scheme:   bdn.NewSchemeOnG2(suite),
+		keyGroup: suite.G1(),
 	}
 }
 
@@ -32,5 +34,5 @@ func (v Verifier) Verify(pubKey gpbft.PubKey, msg, sig []byte) error {
 		return xerrors.Errorf("the public key is a null point")
 	}
 
-	return bdn.Verify(v.suite, pubKeyPoint, msg, sig)
+	return v.scheme.Verify(pubKeyPoint, msg, sig)
 }
diff --git a/sim/sim.go b/sim/sim.go
index 5ad4a813..4422e2d0 100644
--- a/sim/sim.go
+++ b/sim/sim.go
@@ -48,8 +48,8 @@ func FakeSigningBacked() *SigningBacked {
 
 func BLSSigningBacked() *SigningBacked {
 	return &SigningBacked{
-		Signer:   blssig.SignerWithKeyOnG2(),
-		Verifier: blssig.VerifierWithKeyOnG2(),
+		Signer:   blssig.SignerWithKeyOnG1(),
+		Verifier: blssig.VerifierWithKeyOnG1(),
 	}
 }