diff --git a/client/txgen/main.go b/client/txgen/main.go
index 95a877912..9b97e022c 100644
--- a/client/txgen/main.go
+++ b/client/txgen/main.go
@@ -35,6 +35,8 @@ func printVersion(me string) {
 	os.Exit(0)
 }
 
+// The main entrance for the transaction generator program which simulate transactions and send to the network for
+// processing.
 func main() {
 	ip := flag.String("ip", "127.0.0.1", "IP of the node")
 	port := flag.String("port", "9999", "port of the node.")
@@ -155,8 +157,6 @@ func main() {
 	start := time.Now()
 	totalTime := float64(*duration)
 
-	client.InitLookUpIntPriKeyMap()
-
 	for {
 		t := time.Now()
 		if totalTime > 0 && t.Sub(start).Seconds() >= totalTime {
diff --git a/client/utils.go b/client/utils.go
deleted file mode 100644
index d5f31ee8e..000000000
--- a/client/utils.go
+++ /dev/null
@@ -1,50 +0,0 @@
-package client
-
-import (
-	"bytes"
-	"io"
-	"log"
-	"net/http"
-	"sync"
-
-	"github.com/harmony-one/harmony/crypto/pki"
-)
-
-// AddressToIntPriKeyMap is the map from address to private key.
-var AddressToIntPriKeyMap map[[20]byte]int // For convenience, we use int as the secret seed for generating private key
-// AddressToIntPriKeyMapLock is the lock of AddressToIntPriKeyMap.
-var AddressToIntPriKeyMapLock sync.Mutex
-
-// InitLookUpIntPriKeyMap inits AddressToIntPriKeyMap.
-func InitLookUpIntPriKeyMap() {
-	if AddressToIntPriKeyMap == nil {
-		AddressToIntPriKeyMapLock.Lock()
-		AddressToIntPriKeyMap = make(map[[20]byte]int)
-		for i := 1; i <= 10000; i++ {
-			AddressToIntPriKeyMap[pki.GetAddressFromInt(i)] = i
-		}
-		AddressToIntPriKeyMapLock.Unlock()
-	}
-}
-
-// LookUpIntPriKey looks up private key by address.
-func LookUpIntPriKey(address [20]byte) (int, bool) {
-	value, ok := AddressToIntPriKeyMap[address]
-	return value, ok
-}
-
-// DownloadURLAsString downloads url as string.
-func DownloadURLAsString(url string) (string, error) {
-	response, err := http.Get(url)
-	buf := bytes.NewBufferString("")
-	if err != nil {
-		log.Fatal(err)
-	} else {
-		defer response.Body.Close()
-		_, err := io.Copy(buf, response.Body)
-		if err != nil {
-			log.Fatal(err)
-		}
-	}
-	return buf.String(), err
-}
diff --git a/client/wallet/main.go b/client/wallet/main.go
index ff52feb2b..03bc9c1b1 100644
--- a/client/wallet/main.go
+++ b/client/wallet/main.go
@@ -11,19 +11,16 @@ import (
 	"github.com/ethereum/go-ethereum/params"
 	libs "github.com/harmony-one/harmony/beaconchain/libs"
 	"github.com/harmony-one/harmony/beaconchain/rpc"
+	"github.com/harmony-one/harmony/client"
 	client2 "github.com/harmony-one/harmony/client/service"
 	"github.com/harmony-one/harmony/core/types"
-	"github.com/harmony-one/harmony/p2p/p2pimpl"
-	"log"
-	"math/big"
-	"strings"
-
-	"github.com/harmony-one/harmony/client"
 	"github.com/harmony-one/harmony/node"
 	"github.com/harmony-one/harmony/p2p"
+	"github.com/harmony-one/harmony/p2p/p2pimpl"
 	proto_node "github.com/harmony-one/harmony/proto/node"
 	"io"
 	"io/ioutil"
+	"math/big"
 	"os"
 	"path"
 	"strconv"
@@ -42,12 +39,14 @@ func printVersion(me string) {
 	os.Exit(0)
 }
 
-// AccountState includes the state of an account
+// AccountState includes the balance and nonce of an account
 type AccountState struct {
 	balance *big.Int
 	nonce   uint64
 }
 
+// The main wallet program entrance. Note the this wallet program is for demo-purpose only. It does not implement
+// the secure storage of keys.
 func main() {
 	// Account subcommands
 	accountImportCommand := flag.NewFlagSet("import", flag.ExitOnError)
@@ -280,28 +279,6 @@ func convertBalanceIntoReadableFormat(balance *big.Int) string {
 	}
 	return string(bytes)
 }
-func getShardIDToLeaderMap() map[uint32]p2p.Peer {
-	// TODO(ricl): Later use data.harmony.one for API.
-	str, _ := client.DownloadURLAsString("https://s3-us-west-2.amazonaws.com/unique-bucket-bin/leaders.txt")
-	lines := strings.Split(str, "\n")
-	shardIDLeaderMap := map[uint32]p2p.Peer{}
-	log.Print(lines)
-	for _, line := range lines {
-		if line == "" {
-			continue
-		}
-		parts := strings.Split(line, " ")
-
-		shardID := parts[3]
-		id, err := strconv.Atoi(shardID)
-		if err == nil {
-			shardIDLeaderMap[uint32(id)] = p2p.Peer{IP: parts[0], Port: parts[1]}
-		} else {
-			log.Print("[Generator] Error parsing the shard Id ", shardID)
-		}
-	}
-	return shardIDLeaderMap
-}
 
 // CreateWalletNode creates wallet server node.
 func CreateWalletNode() *node.Node {