diff --git a/types/utils.go b/types/utils.go
index dc13af6f9..50074f2b0 100644
--- a/types/utils.go
+++ b/types/utils.go
@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"time"
 
+	"github.com/cosmos/cosmos-sdk/types/kv"
 	dbm "github.com/tendermint/tm-db"
 )
 
@@ -106,3 +107,30 @@ func CopyBytes(bz []byte) (ret []byte) {
 	copy(ret, bz)
 	return ret
 }
+
+// AppendLengthPrefixedBytes combines the slices of bytes to one slice of bytes.
+func AppendLengthPrefixedBytes(args ...[]byte) []byte {
+	length := 0
+	for _, v := range args {
+		length += len(v)
+	}
+	res := make([]byte, length)
+
+	length = 0
+	for _, v := range args {
+		copy(res[length:length+len(v)], v)
+		length += len(v)
+	}
+
+	return res
+}
+
+// ParseLengthPrefixedBytes panics when store key length is not equal to the given length.
+func ParseLengthPrefixedBytes(key []byte, startIndex int, sliceLength int) ([]byte, int) {
+	neededLength := startIndex + sliceLength
+	endIndex := neededLength - 1
+	kv.AssertKeyAtLeastLength(key, neededLength)
+	byteSlice := key[startIndex:neededLength]
+
+	return byteSlice, endIndex
+}
diff --git a/types/utils_test.go b/types/utils_test.go
index c04c9c81f..06576d407 100644
--- a/types/utils_test.go
+++ b/types/utils_test.go
@@ -8,6 +8,7 @@ import (
 	"github.com/stretchr/testify/suite"
 
 	sdk "github.com/cosmos/cosmos-sdk/types"
+	"github.com/cosmos/cosmos-sdk/types/address"
 )
 
 type utilsTestSuite struct {
@@ -109,3 +110,23 @@ func (s *utilsTestSuite) TestParseTimeBytes() {
 	_, err = sdk.ParseTimeBytes([]byte{})
 	s.Require().Error(err)
 }
+
+func (s *utilsTestSuite) TestAppendParseBytes() {
+	test1 := "test1"
+	test2 := "testString2"
+	testByte1 := []byte(test1)
+	testByte2 := []byte(test2)
+
+	combinedBytes := sdk.AppendLengthPrefixedBytes(address.MustLengthPrefix(testByte1), address.MustLengthPrefix(testByte2))
+	testCombineBytes := append([]byte{}, address.MustLengthPrefix(testByte1)...)
+	testCombineBytes = append(testCombineBytes, address.MustLengthPrefix(testByte2)...)
+	s.Require().Equal(combinedBytes, testCombineBytes)
+
+	test1Len, test1LenEndIndex := sdk.ParseLengthPrefixedBytes(combinedBytes, 0, 1)
+	parseTest1, parseTest1EndIndex := sdk.ParseLengthPrefixedBytes(combinedBytes, test1LenEndIndex+1, int(test1Len[0]))
+	s.Require().Equal(testByte1, parseTest1)
+
+	test2Len, test2LenEndIndex := sdk.ParseLengthPrefixedBytes(combinedBytes, parseTest1EndIndex+1, 1)
+	parseTest2, _ := sdk.ParseLengthPrefixedBytes(combinedBytes, test2LenEndIndex+1, int(test2Len[0]))
+	s.Require().Equal(testByte2, parseTest2)
+}
diff --git a/x/authz/keeper/keys.go b/x/authz/keeper/keys.go
index 9a935e5b2..a079b71dd 100644
--- a/x/authz/keeper/keys.go
+++ b/x/authz/keeper/keys.go
@@ -34,14 +34,8 @@ func grantStoreKey(grantee sdk.AccAddress, granter sdk.AccAddress, msgType strin
 	m := conv.UnsafeStrToBytes(msgType)
 	granter = address.MustLengthPrefix(granter)
 	grantee = address.MustLengthPrefix(grantee)
+	key := sdk.AppendLengthPrefixedBytes(GrantKey, granter, grantee, m)
 
-	l := 1 + len(grantee) + len(granter) + len(m)
-	var key = make([]byte, l)
-	copy(key, GrantKey)
-	copy(key[1:], granter)
-	copy(key[1+len(granter):], grantee)
-	copy(key[l-len(m):], m)
-	//	fmt.Println(">>>> len", l, key)
 	return key
 }
 
@@ -49,15 +43,15 @@ func grantStoreKey(grantee sdk.AccAddress, granter sdk.AccAddress, msgType strin
 func parseGrantStoreKey(key []byte) (granterAddr, granteeAddr sdk.AccAddress, msgType string) {
 	// key is of format:
 	// 0x01<granterAddressLen (1 Byte)><granterAddress_Bytes><granteeAddressLen (1 Byte)><granteeAddress_Bytes><msgType_Bytes>
-	kv.AssertKeyAtLeastLength(key, 2)
-	granterAddrLen := key[1] // remove prefix key
-	kv.AssertKeyAtLeastLength(key, int(3+granterAddrLen))
-	granterAddr = sdk.AccAddress(key[2 : 2+granterAddrLen])
-	granteeAddrLen := int(key[2+granterAddrLen])
-	kv.AssertKeyAtLeastLength(key, 4+int(granterAddrLen+byte(granteeAddrLen)))
-	granteeAddr = sdk.AccAddress(key[3+granterAddrLen : 3+granterAddrLen+byte(granteeAddrLen)])
 
-	return granterAddr, granteeAddr, conv.UnsafeBytesToStr(key[3+granterAddrLen+byte(granteeAddrLen):])
+	granterAddrLen, granterAddrLenEndIndex := sdk.ParseLengthPrefixedBytes(key, 1, 1) // ignore key[0] since it is a prefix key
+	granterAddr, granterAddrEndIndex := sdk.ParseLengthPrefixedBytes(key, granterAddrLenEndIndex+1, int(granterAddrLen[0]))
+
+	granteeAddrLen, granteeAddrLenEndIndex := sdk.ParseLengthPrefixedBytes(key, granterAddrEndIndex+1, 1)
+	granteeAddr, granteeAddrEndIndex := sdk.ParseLengthPrefixedBytes(key, granteeAddrLenEndIndex+1, int(granteeAddrLen[0]))
+
+	kv.AssertKeyAtLeastLength(key, granteeAddrEndIndex+1)
+	return granterAddr, granteeAddr, conv.UnsafeBytesToStr(key[(granteeAddrEndIndex + 1):])
 }
 
 // parseGrantQueueKey split expiration time, granter and grantee from the grant queue key
@@ -65,20 +59,18 @@ func parseGrantQueueKey(key []byte) (time.Time, sdk.AccAddress, sdk.AccAddress,
 	// key is of format:
 	// 0x02<grant_expiration_Bytes><granterAddress_Bytes><granteeAddressLen (1 Byte)><granteeAddress_Bytes>
 
-	kv.AssertKeyAtLeastLength(key, 1+lenTime)
-	exp, err := sdk.ParseTimeBytes(key[1 : 1+lenTime])
+	expBytes, expEndIndex := sdk.ParseLengthPrefixedBytes(key, 1, lenTime)
+
+	exp, err := sdk.ParseTimeBytes(expBytes)
 	if err != nil {
 		return exp, nil, nil, err
 	}
 
-	granterAddrLen := key[1+lenTime]
-	kv.AssertKeyAtLeastLength(key, 1+lenTime+int(granterAddrLen))
-	granter := sdk.AccAddress(key[2+lenTime : byte(2+lenTime)+granterAddrLen])
+	granterAddrLen, granterAddrLenEndIndex := sdk.ParseLengthPrefixedBytes(key, expEndIndex+1, 1)
+	granter, granterEndIndex := sdk.ParseLengthPrefixedBytes(key, granterAddrLenEndIndex+1, int(granterAddrLen[0]))
 
-	granteeAddrLen := key[byte(2+lenTime)+granterAddrLen]
-	granteeStart := byte(3+lenTime) + granterAddrLen
-	kv.AssertKeyAtLeastLength(key, int(granteeStart))
-	grantee := sdk.AccAddress(key[granteeStart : granteeStart+granteeAddrLen])
+	granteeAddrLen, granteeAddrLenEndIndex := sdk.ParseLengthPrefixedBytes(key, granterEndIndex+1, 1)
+	grantee, _ := sdk.ParseLengthPrefixedBytes(key, granteeAddrLenEndIndex+1, int(granteeAddrLen[0]))
 
 	return exp, granter, grantee, nil
 }
@@ -92,13 +84,7 @@ func GrantQueueKey(expiration time.Time, granter sdk.AccAddress, grantee sdk.Acc
 	granter = address.MustLengthPrefix(granter)
 	grantee = address.MustLengthPrefix(grantee)
 
-	l := 1 + len(exp) + len(granter) + len(grantee)
-	var key = make([]byte, l)
-	copy(key, GrantQueuePrefix)
-	copy(key[1:], exp)
-	copy(key[1+len(exp):], granter)
-	copy(key[1+len(exp)+len(granter):], grantee)
-	return key
+	return sdk.AppendLengthPrefixedBytes(GrantQueuePrefix, exp, granter, grantee)
 }
 
 // GrantQueueTimePrefix - return grant queue time prefix