diff --git a/beaconchain/beaconchain_handler.go b/beaconchain/beaconchain_handler.go
index c3b7ba6c9..a7a2f0127 100644
--- a/beaconchain/beaconchain_handler.go
+++ b/beaconchain/beaconchain_handler.go
@@ -47,7 +47,7 @@ func (IDC *BeaconChain) BeaconChainHandler(conn net.Conn) {
 	}
 	switch msgCategory {
 	case proto.Identity:
-		actionType := proto_identity.IdentityMessageType(msgType)
+		actionType := proto_identity.IDMessageType(msgType)
 		switch actionType {
 		case proto_identity.Identity:
 			idMsgType, err := proto_identity.GetIdentityMessageType(msgPayload)
diff --git a/crypto/cosi.go b/crypto/cosi.go
index 675616053..4c98c2c69 100644
--- a/crypto/cosi.go
+++ b/crypto/cosi.go
@@ -1,5 +1,5 @@
 /*
-Package cosi implements the collective signing (CoSi) algorithm as presented in
+Package crypto implements the collective signing (CoSi) algorithm as presented in
 the paper "Keeping Authorities 'Honest or Bust' with Decentralized Witness
 Cosigning" by Ewa Syta et al. See https://arxiv.org/abs/1503.08768. This
 package only provides the functionality for the cryptographic operations of
diff --git a/p2p/backoff.go b/p2p/backoff.go
index 2bac92e41..c57a636cb 100644
--- a/p2p/backoff.go
+++ b/p2p/backoff.go
@@ -16,6 +16,7 @@ type BackoffBase struct {
 	Min, Cur, Max time.Duration
 }
 
+// NewBackoffBase creates a new BackOffBase structure
 func NewBackoffBase(min, max time.Duration) *BackoffBase {
 	return &BackoffBase{min, min, max}
 }
@@ -40,21 +41,23 @@ func (b *BackoffBase) Sleep() {
 	}
 }
 
-// Adjust the duration.  Subtypes shall implement this.
+// Backoff adjusts the duration.  Subtypes shall implement this.
 func (b *BackoffBase) Backoff() {
 	// default implementation does not backoff
 }
 
-// Exponential backoff.
+// ExpBackoff is an exponential backoff data structure.
 type ExpBackoff struct {
 	BackoffBase
 	Factor float64
 }
 
+// NewExpBackoff creates a new ExpBackOff structure
 func NewExpBackoff(min, max time.Duration, factor float64) *ExpBackoff {
 	return &ExpBackoff{*NewBackoffBase(min, max), factor}
 }
 
+// Backoff implements the exponential backoff
 func (b *ExpBackoff) Backoff() {
 	b.Cur = time.Duration(float64(b.Cur) * b.Factor)
 }
diff --git a/p2p/helper.go b/p2p/helper.go
index d748a0aae..b38c999d0 100644
--- a/p2p/helper.go
+++ b/p2p/helper.go
@@ -24,9 +24,10 @@ content (n bytes) - actual message content
 
 */
 
-const BATCH_SIZE = 1 << 16
+// BatchSize defines the size of buffer
+const BatchSize = 1 << 16
 
-// Read the message type and content size, and return the actual content.
+// ReadMessageContent reads the message type and content size, and return the actual content.
 func ReadMessageContent(conn net.Conn) ([]byte, error) {
 	var (
 		contentBuf = bytes.NewBuffer([]byte{})
@@ -67,12 +68,12 @@ func ReadMessageContent(conn net.Conn) ([]byte, error) {
 	//log.Printf("The content size is %d bytes.", bytesToRead)
 
 	//// Read the content in chunk of 16 * 1024 bytes
-	tmpBuf := make([]byte, BATCH_SIZE)
+	tmpBuf := make([]byte, BatchSize)
 ILOOP:
 	for {
 		timeoutDuration := 10 * time.Second
 		conn.SetReadDeadline(time.Now().Add(timeoutDuration))
-		if bytesToRead < BATCH_SIZE {
+		if bytesToRead < BatchSize {
 			// Read the last number of bytes less than 1024
 			tmpBuf = make([]byte, bytesToRead)
 		}
@@ -97,6 +98,7 @@ ILOOP:
 	return contentBuf.Bytes(), nil
 }
 
+// CreateMessage create a general message. FIXME: this is not used
 func CreateMessage(msgType byte, data []byte) []byte {
 	buffer := bytes.NewBuffer([]byte{})
 
@@ -110,6 +112,7 @@ func CreateMessage(msgType byte, data []byte) []byte {
 	return buffer.Bytes()
 }
 
+// SendMessageContent send message over net connection. FIXME: this is not used
 func SendMessageContent(conn net.Conn, data []byte) {
 	msgToSend := CreateMessage(byte(1), data)
 	w := bufio.NewWriter(conn)