diff --git a/cmd/harmony/blsloader/loader.go b/cmd/harmony/blsloader/loader.go
index 9c51d936f..bf78bd987 100644
--- a/cmd/harmony/blsloader/loader.go
+++ b/cmd/harmony/blsloader/loader.go
@@ -6,7 +6,7 @@ import (
 	"os"
 	"path/filepath"
 
-	ffibls "github.com/harmony-one/bls/ffi/go/bls"
+	"github.com/harmony-one/bls/ffi/go/bls"
 	"github.com/harmony-one/harmony/multibls"
 )
 
@@ -24,10 +24,10 @@ type Loader struct {
 }
 
 // LoadKeys load all keys from the input fields provided
-func (loader *Loader) LoadKeys() (multibls.PrivateKey, error) {
+func (loader *Loader) LoadKeys() (multibls.PrivateKeys, error) {
 	helper, err := loader.getHelper()
 	if err != nil {
-		return multibls.PrivateKey{}, err
+		return multibls.PrivateKeys{}, err
 	}
 	return helper.loadKeys()
 }
@@ -64,7 +64,7 @@ func (loader *Loader) getHelper() (loadHelper, error) {
 
 // loadHelper defines the interface to help load bls keys
 type loadHelper interface {
-	loadKeys() (multibls.PrivateKey, error)
+	loadKeys() (multibls.PrivateKeys, error)
 }
 
 // basicSingleBlsLoader loads a single bls key file with passphrase
@@ -75,14 +75,14 @@ type basicSingleBlsLoader struct {
 	persistPassphrase bool
 }
 
-func (loader *basicSingleBlsLoader) loadKeys() (multibls.PrivateKey, error) {
+func (loader *basicSingleBlsLoader) loadKeys() (multibls.PrivateKeys, error) {
 	providers, err := loader.getPassProviders()
 	if err != nil {
-		return multibls.PrivateKey{}, err
+		return multibls.PrivateKeys{}, err
 	}
 	secretKey, err := loadBasicKey(loader.blsKeyFile, providers)
 	if err != nil {
-		return multibls.PrivateKey{}, err
+		return multibls.PrivateKeys{}, err
 	}
 	return secretKeyToMultiPrivateKey(secretKey), nil
 }
@@ -126,14 +126,14 @@ type kmsSingleBlsLoader struct {
 	awsConfigFile *string
 }
 
-func (loader *kmsSingleBlsLoader) loadKeys() (multibls.PrivateKey, error) {
+func (loader *kmsSingleBlsLoader) loadKeys() (multibls.PrivateKeys, error) {
 	provider, err := loader.getKmsClientProvider()
 	if err != nil {
-		return multibls.PrivateKey{}, err
+		return multibls.PrivateKeys{}, err
 	}
 	secretKey, err := loadKmsKeyFromFile(loader.awsBlsKey, provider)
 	if err != nil {
-		return multibls.PrivateKey{}, err
+		return multibls.PrivateKeys{}, err
 	}
 	return secretKeyToMultiPrivateKey(secretKey), nil
 }
@@ -170,16 +170,16 @@ type blsDirLoader struct {
 	pps []passProvider
 	kcp kmsClientProvider
 	// result field
-	secretKeys []*ffibls.SecretKey
+	secretKeys []*bls.SecretKey
 }
 
-func (loader *blsDirLoader) loadKeys() (multibls.PrivateKey, error) {
+func (loader *blsDirLoader) loadKeys() (multibls.PrivateKeys, error) {
 	var err error
 	if loader.pps, err = loader.getPassProviders(); err != nil {
-		return multibls.PrivateKey{}, err
+		return multibls.PrivateKeys{}, err
 	}
 	if loader.kcp, err = loader.getKmsClientProvider(); err != nil {
-		return multibls.PrivateKey{}, err
+		return multibls.PrivateKeys{}, err
 	}
 	return loader.loadKeyFiles()
 }
@@ -231,10 +231,10 @@ func (loader *blsDirLoader) getKmsClientProvider() (kmsClientProvider, error) {
 	}
 }
 
-func (loader *blsDirLoader) loadKeyFiles() (multibls.PrivateKey, error) {
+func (loader *blsDirLoader) loadKeyFiles() (multibls.PrivateKeys, error) {
 	err := filepath.Walk(loader.dirPath, loader.processFileWalk)
 	if err != nil {
-		return multibls.PrivateKey{}, err
+		return multibls.PrivateKeys{}, err
 	}
 	return secretKeyToMultiPrivateKey(loader.secretKeys...), nil
 }
@@ -264,9 +264,9 @@ func (loader *blsDirLoader) skippingErrors() []error {
 	}
 }
 
-func (loader *blsDirLoader) loadKeyFromFile(path string, info os.FileInfo) (*ffibls.SecretKey, error) {
+func (loader *blsDirLoader) loadKeyFromFile(path string, info os.FileInfo) (*bls.SecretKey, error) {
 	var (
-		key *ffibls.SecretKey
+		key *bls.SecretKey
 		err error
 	)
 	switch {
diff --git a/cmd/harmony/blsloader/passProvider.go b/cmd/harmony/blsloader/passProvider.go
index b58edc92b..51104ae97 100644
--- a/cmd/harmony/blsloader/passProvider.go
+++ b/cmd/harmony/blsloader/passProvider.go
@@ -28,7 +28,7 @@ type promptPassProvider struct {
 const pwdPromptStr = "Enter passphrase for the BLS key file %s:"
 
 func newPromptPassProvider() *promptPassProvider {
-	return &promptPassProvider{q}
+	return &promptPassProvider{}
 }
 
 func (provider *promptPassProvider) toStr() string {
diff --git a/cmd/harmony/blsloader/utils.go b/cmd/harmony/blsloader/utils.go
index 406d0854e..384311647 100644
--- a/cmd/harmony/blsloader/utils.go
+++ b/cmd/harmony/blsloader/utils.go
@@ -5,7 +5,8 @@ import (
 	"os"
 	"strings"
 
-	ffibls "github.com/harmony-one/bls/ffi/go/bls"
+	bls_core "github.com/harmony-one/bls/ffi/go/bls"
+	"github.com/harmony-one/harmony/crypto/bls"
 	"github.com/harmony-one/harmony/internal/blsgen"
 	"github.com/harmony-one/harmony/multibls"
 	"github.com/pkg/errors"
@@ -19,7 +20,7 @@ var (
 
 // loadBasicKey loads a single bls key through a key file and passphrase combination.
 // The passphrase is provided by a slice of passProviders.
-func loadBasicKey(blsKeyFile string, pps []passProvider) (*ffibls.SecretKey, error) {
+func loadBasicKey(blsKeyFile string, pps []passProvider) (*bls_core.SecretKey, error) {
 	if len(pps) == 0 {
 		return nil, errNilPassProvider
 	}
@@ -33,7 +34,7 @@ func loadBasicKey(blsKeyFile string, pps []passProvider) (*ffibls.SecretKey, err
 	return nil, fmt.Errorf("failed to load bls key %v", blsKeyFile)
 }
 
-func loadBasicKeyWithProvider(blsKeyFile string, pp passProvider) (*ffibls.SecretKey, error) {
+func loadBasicKeyWithProvider(blsKeyFile string, pp passProvider) (*bls_core.SecretKey, error) {
 	pass, err := pp.getPassphrase(blsKeyFile)
 	if err != nil {
 		return nil, errors.Wrapf(err, "unable to get passphrase from %s", pp.toStr())
@@ -46,7 +47,7 @@ func loadBasicKeyWithProvider(blsKeyFile string, pp passProvider) (*ffibls.Secre
 }
 
 // loadKmsKeyFromFile loads a single KMS BLS key from file
-func loadKmsKeyFromFile(blsKeyFile string, kcp kmsClientProvider) (*ffibls.SecretKey, error) {
+func loadKmsKeyFromFile(blsKeyFile string, kcp kmsClientProvider) (*bls_core.SecretKey, error) {
 	if kcp == nil {
 		return nil, errNilKMSClientProvider
 	}
@@ -123,8 +124,13 @@ func promptYesNo(prompt string) (bool, error) {
 	}
 }
 
-func secretKeyToMultiPrivateKey(secretKeys ...*ffibls.SecretKey) multibls.PrivateKey {
-	return multibls.PrivateKey{PrivateKey: secretKeys}
+func secretKeyToMultiPrivateKey(secretKeys ...*bls_core.SecretKey) multibls.PrivateKeys {
+	keys := make(multibls.PrivateKeys, 0, len(secretKeys))
+	for _, secretKey := range secretKeys {
+		key := bls.WrapperFromPrivateKey(secretKey)
+		keys = append(keys, key)
+	}
+	return keys
 }
 
 func stringIsSet(val *string) bool {
diff --git a/crypto/bls/bls.go b/crypto/bls/bls.go
index 0058d7f76..0f291debf 100644
--- a/crypto/bls/bls.go
+++ b/crypto/bls/bls.go
@@ -32,6 +32,19 @@ type PublicKeyWrapper struct {
 	Object *bls.PublicKey
 }
 
+// WrapperFromPrivateKey makes a PrivateKeyWrapper from bls secret key
+func WrapperFromPrivateKey(pri *bls.SecretKey) PrivateKeyWrapper {
+	pub := pri.GetPublicKey()
+	pubBytes := FromLibBLSPublicKeyUnsafe(pub)
+	return PrivateKeyWrapper{
+		Pri: pri,
+		Pub: &PublicKeyWrapper{
+			Bytes:  *pubBytes,
+			Object: pub,
+		},
+	}
+}
+
 // SerializedPublicKey defines the serialized bls public key
 type SerializedPublicKey [PublicKeySizeInBytes]byte
 
diff --git a/multibls/multibls.go b/multibls/multibls.go
index f1e9ed356..5c4568fa8 100644
--- a/multibls/multibls.go
+++ b/multibls/multibls.go
@@ -3,9 +3,8 @@ package multibls
 import (
 	"strings"
 
-	"github.com/harmony-one/harmony/crypto/bls"
-
 	bls_core "github.com/harmony-one/bls/ffi/go/bls"
+	"github.com/harmony-one/harmony/crypto/bls"
 )
 
 // PrivateKeys stores the bls secret keys that belongs to the node
@@ -47,9 +46,11 @@ func (multiKey PrivateKeys) GetPublicKeys() PublicKeys {
 }
 
 // GetPrivateKeys creates a multibls PrivateKeys using bls.SecretKey
-func GetPrivateKeys(key *bls_core.SecretKey) PrivateKeys {
-	pub := key.GetPublicKey()
-	pubWrapper := bls.PublicKeyWrapper{Object: pub}
-	pubWrapper.Bytes.FromLibBLSPublicKey(pub)
-	return PrivateKeys{bls.PrivateKeyWrapper{Pri: key, Pub: &pubWrapper}}
+func GetPrivateKeys(secretKeys ...*bls_core.SecretKey) PrivateKeys {
+	keys := make(PrivateKeys, 0, len(secretKeys))
+	for _, secretKey := range secretKeys {
+		key := bls.WrapperFromPrivateKey(secretKey)
+		keys = append(keys, key)
+	}
+	return keys
 }