diff --git a/certification/bls/bls.go b/certification/bls/bls.go
index f0ebeab..7f3b68d 100644
--- a/certification/bls/bls.go
+++ b/certification/bls/bls.go
@@ -1,70 +1,101 @@
 package bls
 
-import "github.com/herumi/bls-go-binary/bls"
-
-const (
-	dstG1              = "BLS_SIG_BLS12381G1_XMD:SHA-256_SSWU_RO_NUL_"
-	publicKeyGenerator = "1 0x24aa2b2f08f0a91260805272dc51051c6e47ad4fa403b02b4510b647ae3d1770bac0326a805bbefd48056c8c121bdb8 0x13e02b6052719f607dacd3a088274f65596bd0d09920b61ab5da61bbdc7f5049334cf11213945d57e5ac7d055d042b7e 0x0ce5d527727d6e118cc9cdc6da2e351aadfd9baa8cbdd3a76d429a695160d12c923ac9cc3baca289e193548608b82801 0x0606c4a02ea734cc32acd2b02bc28b99cb3e287e85a763af267492ab572e99ab3f370d275cec1da1aaa9075ff05f79be"
+import (
+	"encoding/hex"
+	"github.com/consensys/gnark-crypto/ecc/bls12-381"
+	"github.com/consensys/gnark-crypto/ecc/bls12-381/fr"
+	"math/big"
 )
 
-func init() {
-	if err := bls.Init(bls.BLS12_381); err != nil {
-		panic(err)
-	}
-
-	// Set Ethereum serialization format.
-	bls.SetETHserialization(true)
-	if err := bls.SetMapToMode(bls.IRTF); err != nil {
-		panic(err)
-	}
+const dstG1 = "BLS_SIG_BLS12381G1_XMD:SHA-256_SSWU_RO_NUL_"
 
-	// Set the generator of G2. see https://www.ietf.org/archive/id/draft-irtf-cfrg-pairing-friendly-curves-11.html#section-4.2.1
-	var gen bls.PublicKey
-	if err := gen.SetHexString(publicKeyGenerator); err != nil {
-		panic(err)
-	}
-	if err := bls.SetGeneratorOfPublicKey(&gen); err != nil {
-		panic(err)
-	}
+var (
+	g2, g2Gen bls12381.G2Affine
+)
 
-	if err := bls.SetDstG1(dstG1); err != nil {
-		panic(err)
-	}
+func init() {
+	_, _, _, g2Gen = bls12381.Generators()
+	g2.Neg(&g2Gen)
 }
 
-type PublicKey = bls.PublicKey
+type PublicKey bls12381.G2Affine
 
 // PublicKeyFromBytes returns a PublicKey from a byte slice.
 func PublicKeyFromBytes(b []byte) (*PublicKey, error) {
-	var pub bls.PublicKey
-	return &pub, pub.Deserialize(b)
+	var g2 bls12381.G2Affine
+	if err := g2.Unmarshal(b); err != nil {
+		return nil, err
+	}
+	return (*PublicKey)(&g2), nil
 }
 
 // PublicKeyFromHexString returns a PublicKey from a hex string.
 func PublicKeyFromHexString(s string) (*PublicKey, error) {
-	var pub bls.PublicKey
-	return &pub, pub.DeserializeHexStr(s)
+	raw, err := hex.DecodeString(s)
+	if err != nil {
+		return nil, err
+	}
+	return PublicKeyFromBytes(raw)
 }
 
-type SecretKey = bls.SecretKey
+type SecretKey fr.Element
 
 // NewSecretKeyByCSPRNG returns a new SecretKey generated by CSPRNG.
 func NewSecretKeyByCSPRNG() *SecretKey {
-	var sk bls.SecretKey
-	sk.SetByCSPRNG()
-	return &sk
+	var e fr.Element
+	if _, err := e.SetRandom(); err != nil {
+		return nil
+	}
+	return (*SecretKey)(&e)
+}
+
+func (sk *SecretKey) GetPublicKey() *PublicKey {
+	e := fr.Element(*sk)
+	pk := g2Gen.ScalarMultiplication(
+		&g2Gen,
+		e.BigInt(big.NewInt(0)),
+	)
+	return (*PublicKey)(pk)
+}
+
+func (sk *SecretKey) Sign(msg []byte) *Signature {
+	e := fr.Element(*sk)
+	g1, _ := bls12381.HashToG1(msg, []byte(dstG1))
+	sig := g1.ScalarMultiplication(
+		&g1,
+		e.BigInt(big.NewInt(0)),
+	)
+	return (*Signature)(sig)
 }
 
-type Signature = bls.Sign
+type Signature bls12381.G1Affine
 
 // SignatureFromBytes returns a Signature from a byte slice.
 func SignatureFromBytes(b []byte) (*Signature, error) {
-	var sig bls.Sign
-	return &sig, sig.Deserialize(b)
+	var sig bls12381.G1Affine
+	if _, err := sig.SetBytes(b); err != nil {
+		return nil, err
+	}
+	return (*Signature)(&sig), nil
 }
 
 // SignatureFromHexString returns a Signature from a hex string.
 func SignatureFromHexString(s string) (*Signature, error) {
-	var sig bls.Sign
-	return &sig, sig.DeserializeHexStr(s)
+	raw, err := hex.DecodeString(s)
+	if err != nil {
+		return nil, err
+	}
+	return SignatureFromBytes(raw)
+}
+
+// Verify returns true if the signature is valid for the message.
+func (sig *Signature) Verify(pk *PublicKey, msg []byte) bool {
+	g1, _ := bls12381.HashToG1(msg, []byte(dstG1))
+	valid, err := bls12381.PairingCheck(
+		[]bls12381.G1Affine{bls12381.G1Affine(*sig), g1},
+		[]bls12381.G2Affine{g2, bls12381.G2Affine(*pk)})
+	if err != nil {
+		return false
+	}
+	return valid
 }
diff --git a/certification/bls/bls_test.go b/certification/bls/bls_test.go
index 5811088..0da6bdc 100644
--- a/certification/bls/bls_test.go
+++ b/certification/bls/bls_test.go
@@ -6,9 +6,9 @@ import (
 )
 
 func TestSecretKey(t *testing.T) {
+	msg := []byte("hello")
 	sk := NewSecretKeyByCSPRNG()
-	s := sk.Sign("hello")
-	if !s.Verify(sk.GetPublicKey(), "hello") {
+	if !sk.Sign(msg).Verify(sk.GetPublicKey(), msg) {
 		t.Error()
 	}
 }
@@ -29,10 +29,10 @@ func TestVerify(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	if signature.Verify(publicKey, "bye") {
+	if signature.Verify(publicKey, []byte("bye")) {
 		t.Error()
 	}
-	if !signature.Verify(publicKey, "hello") {
+	if !signature.Verify(publicKey, []byte("hello")) {
 		t.Error()
 	}
 }
@@ -51,10 +51,10 @@ func TestVerify_hex(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	if signature.Verify(publicKey, "bye") {
+	if signature.Verify(publicKey, []byte("bye")) {
 		t.Error()
 	}
-	if !signature.Verify(publicKey, "hello") {
+	if !signature.Verify(publicKey, []byte("hello")) {
 		t.Error()
 	}
 }
diff --git a/certification/certificate.go b/certification/certificate.go
index 3082615..058ce58 100644
--- a/certification/certificate.go
+++ b/certification/certificate.go
@@ -163,7 +163,7 @@ func verifyCertificateSignature(certificate Certificate, publicKey *bls.PublicKe
 	if err != nil {
 		return err
 	}
-	if !signature.VerifyByte(publicKey, message) {
+	if !signature.Verify(publicKey, message) {
 		return fmt.Errorf("signature verification failed")
 	}
 	return nil
diff --git a/go.mod b/go.mod
index 2272231..7f8103b 100644
--- a/go.mod
+++ b/go.mod
@@ -5,10 +5,17 @@ go 1.22.1
 require (
 	github.com/aviate-labs/leb128 v0.3.0
 	github.com/aviate-labs/secp256k1 v0.0.0-5e6736a
+	github.com/consensys/gnark-crypto v0.13.0
 	github.com/di-wu/parser v0.3.0
 	github.com/fxamacker/cbor/v2 v2.6.0
-	github.com/herumi/bls-go-binary v1.34.0
 	google.golang.org/protobuf v1.34.1
 )
 
-require github.com/x448/float16 v0.8.4 // indirect
+require (
+	github.com/bits-and-blooms/bitset v1.7.0 // indirect
+	github.com/consensys/bavard v0.1.13 // indirect
+	github.com/mmcloughlin/addchain v0.4.0 // indirect
+	github.com/x448/float16 v0.8.4 // indirect
+	golang.org/x/sys v0.15.0 // indirect
+	rsc.io/tmplfunc v0.0.3 // indirect
+)
diff --git a/go.sum b/go.sum
index 9ade8c0..3f3a917 100644
--- a/go.sum
+++ b/go.sum
@@ -2,17 +2,41 @@ github.com/aviate-labs/leb128 v0.3.0 h1:s9htRv3OYk8nuHqJu9PiVFJxv1jIUTIcpEeiURa9
 github.com/aviate-labs/leb128 v0.3.0/go.mod h1:GclhBOjhIKmcDlgHKhj0AEZollzERfZUbcRUKiQVqgY=
 github.com/aviate-labs/secp256k1 v0.0.0-5e6736a h1:aQkG/D+l8Y7tr809l8pN+KebH2jzacWReSFQmeEKFgM=
 github.com/aviate-labs/secp256k1 v0.0.0-5e6736a/go.mod h1:C/lr3F9TimrVkdZckG5mz+VU0TrmpeyVKUjzv2YyGwA=
+github.com/bits-and-blooms/bitset v1.7.0 h1:YjAGVd3XmtK9ktAbX8Zg2g2PwLIMjGREZJHlV4j7NEo=
+github.com/bits-and-blooms/bitset v1.7.0/go.mod h1:gIdJ4wp64HaoK2YrL1Q5/N7Y16edYb8uY+O0FJTyyDA=
+github.com/consensys/bavard v0.1.13 h1:oLhMLOFGTLdlda/kma4VOJazblc7IM5y5QPd2A/YjhQ=
+github.com/consensys/bavard v0.1.13/go.mod h1:9ItSMtA/dXMAiL7BG6bqW2m3NdSEObYWoH223nGHukI=
+github.com/consensys/gnark-crypto v0.13.0 h1:VPULb/v6bbYELAPTDFINEVaMTTybV5GLxDdcjnS+4oc=
+github.com/consensys/gnark-crypto v0.13.0/go.mod h1:wKqwsieaKPThcFkHe0d0zMsbHEUWFmZcG7KBCse210o=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/di-wu/parser v0.3.0 h1:NMOvy5ifswgt4gsdhySVcKOQtvjC43cHZIfViWctqQY=
 github.com/di-wu/parser v0.3.0/go.mod h1:SLp58pW6WamdmznrVRrw2NTyn4wAvT9rrEFynKX7nYo=
 github.com/fxamacker/cbor/v2 v2.6.0 h1:sU6J2usfADwWlYDAFhZBQ6TnLFBHxgesMrQfQgk1tWA=
 github.com/fxamacker/cbor/v2 v2.6.0/go.mod h1:pxXPTn3joSm21Gbwsv0w9OSA2y1HFR9qXEeXQVeNoDQ=
 github.com/google/go-cmp v0.5.5 h1:Khx7svrCpmxxtHBq5j2mp/xVjsi8hQMfNLvJFAlrGgU=
 github.com/google/go-cmp v0.5.5/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
-github.com/herumi/bls-go-binary v1.34.0 h1:x1sKp8zzx+alvlifB+vbA0KkY0Pz4Br31cZ/saDkiFE=
-github.com/herumi/bls-go-binary v1.34.0/go.mod h1:O4Vp1AfR4raRGwFeQpr9X/PQtncEicMoOe6BQt1oX0Y=
+github.com/google/subcommands v1.2.0/go.mod h1:ZjhPrFU+Olkh9WazFPsl27BQ4UPiG37m3yTrtFlrHVk=
+github.com/leanovate/gopter v0.2.9 h1:fQjYxZaynp97ozCzfOyOuAGOU4aU/z37zf/tOujFk7c=
+github.com/leanovate/gopter v0.2.9/go.mod h1:U2L/78B+KVFIx2VmW6onHJQzXtFb+p5y3y2Sh+Jxxv8=
+github.com/mmcloughlin/addchain v0.4.0 h1:SobOdjm2xLj1KkXN5/n0xTIWyZA2+s99UCY1iPfkHRY=
+github.com/mmcloughlin/addchain v0.4.0/go.mod h1:A86O+tHqZLMNO4w6ZZ4FlVQEadcoqkyU72HC5wJ4RlU=
+github.com/mmcloughlin/profile v0.1.1/go.mod h1:IhHD7q1ooxgwTgjxQYkACGA77oFTDdFVejUS1/tS/qU=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/testify v1.8.2 h1:+h33VjcLVPDHtOdpUCuF+7gSuG3yGIftsP1YvFihtJ8=
+github.com/stretchr/testify v1.8.2/go.mod h1:w2LPCIKwWwSfY2zedu0+kehJoqGctiVI29o6fzry7u4=
 github.com/x448/float16 v0.8.4 h1:qLwI1I70+NjRFUR3zs1JPUCgaCXSh3SW62uAKT1mSBM=
 github.com/x448/float16 v0.8.4/go.mod h1:14CWIYCyZA/cWjXOioeEpHeN/83MdbZDRQHoFcYsOfg=
+golang.org/x/sys v0.15.0 h1:h48lPFYpsTvQJZF4EKyI4aLHaev3CxivZmv7yZig9pc=
+golang.org/x/sys v0.15.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543 h1:E7g+9GITq07hpfrRu66IVDexMakfv52eLZ2CXBWiKr4=
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 google.golang.org/protobuf v1.34.1 h1:9ddQBjfCyZPOHPUiPxpYESBLc+T8P3E+Vo4IbKZgFWg=
 google.golang.org/protobuf v1.34.1/go.mod h1:c6P6GXX6sHbq/GpV6MGZEdwhWPcYBgnhAHhKbcUYpos=
+gopkg.in/yaml.v2 v2.4.0 h1:D8xgwECY7CYvx+Y2n4sBz93Jn9JRvxdiyyo8CTfuKaY=
+gopkg.in/yaml.v2 v2.4.0/go.mod h1:RDklbk79AGWmwhnvt/jBztapEOGDOx6ZbXqjP6csGnQ=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
+rsc.io/tmplfunc v0.0.3 h1:53XFQh69AfOa8Tw0Jm7t+GV7KZhOi6jzsCzTtKbMvzU=
+rsc.io/tmplfunc v0.0.3/go.mod h1:AG3sTPzElb1Io3Yg4voV9AGZJuleGAwaVRxL9M49PhA=