add code comment

Signed-off-by: Kaoutar <[email protected]>

token/core/zkatdlog/crypto/common/array.go

@@ -7,8 +7,8 @@ SPDX-License-Identifier: Apache-2.0
 package common
 
 import (
+	"bytes"
 	"encoding/hex"
-	"encoding/json"
 
 	math "github.com/IBM/mathlib"
 	"github.com/pkg/errors"
@@ -23,16 +23,16 @@ type G1Array []*math.G1
 
 // Bytes serialize an array of G1 elements
 func (a *G1Array) Bytes() ([]byte, error) {
-	raw := make([][]byte, 2*len([]*math.G1(*a)))
+	raw := make([][]byte, len([]*math.G1(*a)))
 	for i, e := range []*math.G1(*a) {
 		if e == nil {
 			return nil, errors.Errorf("failed to marshal array of G1")
 		}
 		st := hex.EncodeToString(e.Bytes())
-		raw[2*i] = []byte(st)
-		raw[2*i+1] = []byte(Separator)
+		raw[i] = []byte(st)
 	}
-	return json.Marshal(raw)
+	// join the serialization of the group elements with the predefined separator.
+	return bytes.Join(raw, []byte(Separator)), nil
 }
 
 // GetG1Array takes a series of G1 elements and returns the corresponding array