diff --git a/internal/service/api/handlers/register.go b/internal/service/api/handlers/register.go
index 549fd00..59543e7 100644
--- a/internal/service/api/handlers/register.go
+++ b/internal/service/api/handlers/register.go
@@ -13,7 +13,6 @@ import (
 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/google/jsonapi"
-	"github.com/iden3/go-iden3-crypto/keccak256"
 	"github.com/iden3/go-iden3-crypto/poseidon"
 	"github.com/iden3/go-rapidsnark/verifier"
 	errors2 "github.com/pkg/errors"
@@ -280,7 +279,7 @@ func Register(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	signature, err := crypto.Sign(keccak256.Hash(signedData), api.KeysConfig(r).SignatureKey)
+	signature, err := crypto.Sign(utils.ToEthSignedMessageHash(signedData), api.KeysConfig(r).SignatureKey)
 	if err != nil {
 		log.WithError(err).Error("failed to sign messageHash")
 		jsonError = append(jsonError, problems.InternalError())
diff --git a/internal/utils/asn1_operations.go b/internal/utils/asn1_operations.go
index 269db16..4fc18e0 100644
--- a/internal/utils/asn1_operations.go
+++ b/internal/utils/asn1_operations.go
@@ -10,6 +10,7 @@ import (
 	"math/big"
 
 	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/iden3/go-iden3-crypto/poseidon"
 	"github.com/rarimo/passport-identity-provider/internal/types"
 	"gitlab.com/distributed_lab/logan/v3/errors"
@@ -128,6 +129,11 @@ func ExtractPublicKey(dg15 []byte) (interface{}, [32]byte, error) {
 	}
 }
 
+func ToEthSignedMessageHash(data []byte) []byte {
+	prefix := []byte("\x19Ethereum Signed Message:\n32")
+	return crypto.Keccak256(append(prefix, data...))
+}
+
 func generalPublicKeyExtraction(dg15 []byte) (any, error) {
 	var rawDg15 asn1.RawValue
 	if _, err := asn1.Unmarshal(dg15, &rawDg15); err != nil {