diff --git a/examples/multipro/echo.go b/examples/multipro/echo.go
index 158a54a8..609f458f 100644
--- a/examples/multipro/echo.go
+++ b/examples/multipro/echo.go
@@ -12,6 +12,7 @@ import (
 	"github.com/ipfs/go-ipfs/thirdparty/assert"
 	p2p "github.com/libp2p/go-libp2p/examples/multipro/pb"
 	protobufCodec "github.com/multiformats/go-multicodec/protobuf"
+	"gx/ipfs/QmRS46AyqtpJBsf1zmQdeizSDEzo1qkWR7rdEuPFAv8237/go-libp2p-host"
 )
 
 // pattern: /protocol-name/request-or-response-message/version
@@ -51,13 +52,23 @@ func (e EchoProtocol) onEchoRequest(s inet.Stream) {
 		MessageData: NewMessageData(e.node.ID().String(), data.MessageData.Id, false),
 		Message:     data.Message}
 
+	// sign the data
+	signature, err := e.node.signProtoMessage(resp)
+	if err != nil {
+		log.Fatal("failed to sign response")
+		return
+	}
+
+	// add the signature to the message
+	resp.MessageData.Sign = string(signature)
+
 	s, respErr := e.node.NewStream(context.Background(), s.Conn().RemotePeer(), echoResponse)
 	if respErr != nil {
 		log.Fatal(respErr)
 		return
 	}
 
-	ok := sendDataObject(resp, s)
+	ok := sendProtoMessage(resp, s)
 
 	if ok {
 		log.Printf("%s: Echo response to %s sent.", s.Conn().LocalPeer().String(), s.Conn().RemotePeer().String())
@@ -89,21 +100,30 @@ func (e EchoProtocol) onEchoResponse(s inet.Stream) {
 	e.done <- true
 }
 
-func (e EchoProtocol) Echo(node *Node) bool {
-	log.Printf("%s: Sending echo to: %s....", e.node.ID(), node.ID())
+func (e EchoProtocol) Echo(host host.Host) bool {
+	log.Printf("%s: Sending echo to: %s....", e.node.ID(), host.ID())
 
 	// create message data
 	req := &p2p.EchoRequest{
 		MessageData: NewMessageData(e.node.ID().String(), uuid.New().String(), false),
 		Message:     fmt.Sprintf("Echo from %s", e.node.ID())}
 
-	s, err := e.node.NewStream(context.Background(), node.ID(), echoRequest)
+	signature, err := e.node.signProtoMessage(req)
+	if err != nil {
+		log.Fatal("failed to sign message")
+		return false
+	}
+
+	// add the signature to the message
+	req.MessageData.Sign = string(signature)
+
+	s, err := e.node.NewStream(context.Background(), host.ID(), echoRequest)
 	if err != nil {
 		log.Fatal(err)
 		return false
 	}
 
-	ok := sendDataObject(req, s)
+	ok := sendProtoMessage(req, s)
 
 	if !ok {
 		return false
@@ -111,6 +131,6 @@ func (e EchoProtocol) Echo(node *Node) bool {
 
 	// store request so response handler has access to it
 	e.requests[req.MessageData.Id] = req
-	log.Printf("%s: Echo to: %s was sent. Message Id: %s, Message: %s", e.node.ID(), node.ID(), req.MessageData.Id, req.Message)
+	log.Printf("%s: Echo to: %s was sent. Message Id: %s, Message: %s", e.node.ID(), host.ID(), req.MessageData.Id, req.Message)
 	return true
 }
diff --git a/examples/multipro/main.go b/examples/multipro/main.go
index d6f7a1aa..13d690e5 100644
--- a/examples/multipro/main.go
+++ b/examples/multipro/main.go
@@ -47,10 +47,10 @@ func main() {
 	log.Printf("This is a conversation between %s and %s\n", h1.ID(), h2.ID())
 
 	// send messages using the protocols
-	h1.Ping(h2)
-	h2.Ping(h1)
-	h1.Echo(h2)
-	h2.Echo(h1)
+	h1.Ping(h2.Host)
+	h2.Ping(h1.Host)
+	h1.Echo(h2.Host)
+	h2.Echo(h1.Host)
 
 	// block until all responses have been processed
 	for i := 0; i < 4; i++ {
diff --git a/examples/multipro/node.go b/examples/multipro/node.go
index 0a10d574..7771e1a4 100644
--- a/examples/multipro/node.go
+++ b/examples/multipro/node.go
@@ -3,8 +3,19 @@ package main
 import (
 	host "gx/ipfs/QmRS46AyqtpJBsf1zmQdeizSDEzo1qkWR7rdEuPFAv8237/go-libp2p-host"
 	peer "gx/ipfs/QmXYjuNuxVzXKJCfWasQk1RqkhVLDM9jtUKhqc2WPQmFSB/go-libp2p-peer"
+	"github.com/gogo/protobuf/proto"
 )
 
+func (n Node) signProtoMessage(message proto.Message) ([]byte, error) {
+	// sign the data
+	data, err := proto.Marshal(message)
+	if err != nil {
+		return nil, err
+	}
+
+	return n.signData(data)
+}
+
 func (n Node) signData(data []byte) ([]byte, error) {
 	key := n.Peerstore().PrivKey(n.ID())
 	res, err := key.Sign(data)
@@ -17,11 +28,12 @@ func (n Node) verifyData(data []byte, signature []byte, signerHostId peer.ID) bo
 	return res == true && err == nil
 }
 
-// Node type - implements one or more p2p protocols
+// Node type - a host with one or more implemented p2p protocols
 type Node struct {
 	host.Host     // lib-p2p host
 	*PingProtocol // ping protocol impl
 	*EchoProtocol // echo protocol impl
+	// add other protocols here...
 }
 
 // create a new node with its implemented protocols
diff --git a/examples/multipro/ping.go b/examples/multipro/ping.go
index eec20668..06d60d05 100644
--- a/examples/multipro/ping.go
+++ b/examples/multipro/ping.go
@@ -11,6 +11,7 @@ import (
 	uuid "github.com/google/uuid"
 	p2p "github.com/libp2p/go-libp2p/examples/multipro/pb"
 	protobufCodec "github.com/multiformats/go-multicodec/protobuf"
+	"gx/ipfs/QmRS46AyqtpJBsf1zmQdeizSDEzo1qkWR7rdEuPFAv8237/go-libp2p-host"
 )
 
 // pattern: /protocol-name/request-or-response-message/version
@@ -45,18 +46,29 @@ func (p PingProtocol) onPingRequest(s inet.Stream) {
 
 	log.Printf("%s: Received ping request from %s. Message: %s", s.Conn().LocalPeer(), s.Conn().RemotePeer(), data.Message)
 
-	// send response to sender
+	// generate response message
 	log.Printf("%s: Sending ping response to %s. Message id: %s...", s.Conn().LocalPeer(), s.Conn().RemotePeer(), data.MessageData.Id)
 	resp := &p2p.PingResponse{MessageData: NewMessageData(p.node.ID().String(), data.MessageData.Id, false),
 		Message: fmt.Sprintf("Ping response from %s", p.node.ID())}
 
+	// sign the data
+	signature, err := p.node.signProtoMessage(resp)
+	if err != nil {
+		log.Fatal("failed to sign response")
+		return
+	}
+
+	// add the signature to the message
+	resp.MessageData.Sign = string(signature)
+
+	// send the response
 	s, respErr := p.node.NewStream(context.Background(), s.Conn().RemotePeer(), pingResponse)
 	if respErr != nil {
 		log.Fatal(respErr)
 		return
 	}
 
-	ok := sendDataObject(resp, s)
+	ok := sendProtoMessage(resp, s)
 
 	if ok {
 		log.Printf("%s: Ping response to %s sent.", s.Conn().LocalPeer().String(), s.Conn().RemotePeer().String())
@@ -86,20 +98,30 @@ func (p PingProtocol) onPingResponse(s inet.Stream) {
 	p.done <- true
 }
 
-func (p PingProtocol) Ping(node *Node) bool {
-	log.Printf("%s: Sending ping to: %s....", p.node.ID(), node.ID())
+func (p PingProtocol) Ping(host host.Host) bool {
+	log.Printf("%s: Sending ping to: %s....", p.node.ID(), host.ID())
 
 	// create message data
 	req := &p2p.PingRequest{MessageData: NewMessageData(p.node.ID().String(), uuid.New().String(), false),
 		Message: fmt.Sprintf("Ping from %s", p.node.ID())}
 
-	s, err := p.node.NewStream(context.Background(), node.Host.ID(), pingRequest)
+	// sign the data
+	signature, err := p.node.signProtoMessage(req)
+	if err != nil {
+		log.Fatal("failed to sign pb data")
+		return false
+	}
+
+	// add the signature to the message
+	req.MessageData.Sign = string(signature)
+
+	s, err := p.node.NewStream(context.Background(), host.ID(), pingRequest)
 	if err != nil {
 		log.Fatal(err)
 		return false
 	}
 
-	ok := sendDataObject(req, s)
+	ok := sendProtoMessage(req, s)
 
 	if !ok {
 		return false
@@ -107,6 +129,6 @@ func (p PingProtocol) Ping(node *Node) bool {
 
 	// store ref request so response handler has access to it
 	p.requests[req.MessageData.Id] = req
-	log.Printf("%s: Ping to: %s was sent. Message Id: %s, Message: %s", p.node.ID(), node.ID(), req.MessageData.Id, req.Message)
+	log.Printf("%s: Ping to: %s was sent. Message Id: %s, Message: %s", p.node.ID(), host.ID(), req.MessageData.Id, req.Message)
 	return true
 }
diff --git a/examples/multipro/protocol.go b/examples/multipro/protocol.go
index b2672342..6cf849d4 100644
--- a/examples/multipro/protocol.go
+++ b/examples/multipro/protocol.go
@@ -9,6 +9,7 @@ import (
 	"time"
 	//host "gx/ipfs/QmRS46AyqtpJBsf1zmQdeizSDEzo1qkWR7rdEuPFAv8237/go-libp2p-host"
 	//"bytes"
+	"github.com/gogo/protobuf/proto"
 )
 
 // node version
@@ -17,7 +18,7 @@ const clientVersion = "go-p2p-node/0.0.1"
 // helper method - writes a protobuf go data object to a network stream
 // data - reference of protobuf go data object to send (not the object itself)
 // s - network stream to write the data to
-func sendDataObject(data interface{}, s inet.Stream) bool {
+func sendProtoMessage(data proto.Message, s inet.Stream) bool {
 	writer := bufio.NewWriter(s)
 	enc := protobufCodec.Multicodec(nil).Encoder(writer)
 	err := enc.Encode(data)