diff --git a/index.html b/index.html
index 3e3b8e05f..b8b22c012 100644
--- a/index.html
+++ b/index.html
@@ -129,7 +129,7 @@
               <div class="large-6 columns">
                 <h3>Join a Wallet in Creation</h3>
               <input type="text" class="form-control" placeholder="Paste wallet secret here"
-                 ng-model="connectionId" required ng-minlength="32" ng-maxlength="32" autofocus>
+                 ng-model="connectionId" required autofocus>
               </div>
               <div class="large-3 columns">
                 <button class="button primary expand round"
@@ -202,8 +202,8 @@
 
           <ul class="no-bullet">
             <li class="panel" ng-repeat="copayer in $root.wallet.network.connectedCopayers()">
-              <span ng-if="copayer === $root.wallet.getMyCopayerId()"> You ({{copayer}})</span>
-              <span ng-if="copayer !==  $root.wallet.getMyCopayerId()">{{copayer}}</span>
+              <span ng-if="copayer === $root.wallet.getMyCopayerId()"> You </span>
+              {{copayer}}
               <span>
                   <i class="fi-check size-16 panel-sign right p5h br100"></i>
               </span>
@@ -279,9 +279,8 @@
                       <tr ng-repeat="(peer, actions) in tx.peerActions">
                         <td colspan="3">
                           <div class="panel status">
-                            <span ng-if="peer == $root.wallet.network.peerId"> You
-                            </span>
-                            <span ng-if="peer != $root.wallet.network.peerId"> {{peer}}</span>
+                            <span ng-if="peer === $root.wallet.getMyCopayerId()"> You</span>
+                             {{peer}}
 
                             <span ng-repeat="(action, ts) in actions">
                               <span ng-if="action == 'create'" title="{{ts | date:'medium'}}" class="fi-page-add size-18 right m10h"></span>
@@ -492,6 +491,7 @@
     <script src="lib/peerjs/peer.js"></script>
     <script src="lib/bitcore.js"></script>
     <script src="lib/crypto-js/rollups/aes.js"></script>
+    <script src="lib/crypto-js/rollups/hmac-sha256.js"></script>
     <script src="lib/file-saver/FileSaver.js"></script>
     <script src="lib/socket.io.js"></script>
     <script src="js/copayBundle.js"></script>
diff --git a/js/controllers/transactions.js b/js/controllers/transactions.js
index af3404056..fed674948 100644
--- a/js/controllers/transactions.js
+++ b/js/controllers/transactions.js
@@ -60,7 +60,7 @@ angular.module('copay.transactions').controller('TransactionsController',
         return;
       }
       var p = w.txProposals.getTxProposal(ntxid);
-      if (p.txp.builder.isFullySigned()) {
+      if (p.builder.isFullySigned()) {
         $scope.send(ntxid);
         _updateTxs();
         $rootScope.$digest();    
diff --git a/js/models/core/PrivateKey.js b/js/models/core/PrivateKey.js
index 589dfaae0..6fdc21a44 100644
--- a/js/models/core/PrivateKey.js
+++ b/js/models/core/PrivateKey.js
@@ -18,13 +18,22 @@ function PrivateKey(opts) {
   this.privateKeyCache = opts.privateKeyCache || {};
 };
 
-PrivateKey.prototype.getId = function(prefix) {
-  var buf = this.bip.extendedPublicKey;
-  if (prefix) {
-    buf = Buffer.concat([prefix, buf]);
+PrivateKey.prototype.getId = function() {
+  if (!this.id) {
+    var path = PublicKeyRing.SIGNING_BRANCH;
+    var bip32 = this.bip.derive(path);
+    this.id= bip32.eckey.public.toString('hex');
   }
-  var hash = util.sha256(buf).toString('hex');
-  return hash.substring(0, hash.length/2);
+  return this.id;
+};
+
+PrivateKey.prototype.getSigningKey = function() {
+  if (!this.sid) {
+    var path = PublicKeyRing.SIGNING_BRANCH;
+    var bip32 = this.bip.derive(path);
+    this.sid= bip32.eckey.private.toString('hex');
+  }
+  return this.sid;
 };
 
 PrivateKey.fromObj = function(obj) {
diff --git a/js/models/core/PublicKeyRing.js b/js/models/core/PublicKeyRing.js
index a9a1327d5..6d757671f 100644
--- a/js/models/core/PublicKeyRing.js
+++ b/js/models/core/PublicKeyRing.js
@@ -44,9 +44,12 @@ function PublicKeyRing(opts) {
  */
 
 PublicKeyRing.Branch = function (index, isChange) {
-  return 'm/'+(isChange?1:0)+'/'+index;
+  // first 0 is for future use: could be copayerId.
+  return 'm/0/'+(isChange?1:0)+'/'+index;
 };
 
+PublicKeyRing.SIGNING_BRANCH = 'm/100/0/0';
+
 PublicKeyRing.fromObj = function (data) {
   if (data instanceof PublicKeyRing) {
     throw new Error('bad data format: Did you use .toObj()?');
@@ -77,17 +80,20 @@ PublicKeyRing.prototype.serialize = function () {
   return JSON.stringify(this.toObj());
 };
 
-PublicKeyRing.prototype.getCopayerId = function(i, prefix) {
-  var buf = this.copayersBIP32[i].extendedPublicKey;
-  if (prefix) {
-    buf = Buffer.concat([prefix, buf]);
+PublicKeyRing.prototype.getCopayerId = function(i) {
+  this.copayerIds = this.copayerIds  || [];
+
+  if (!this.copayerIds[i]) {
+    var path = PublicKeyRing.SIGNING_BRANCH;
+    var bip32 = this.copayersBIP32[i].derive(path);
+    this.copayerIds[i]= bip32.eckey.public.toString('hex');
   }
-  var hash = util.sha256(buf).toString('hex');
-  return hash.substring(0, hash.length/2);
+
+  return this.copayerIds[i];
 };
 
-PublicKeyRing.prototype.myCopayerId = function(i, prefix) {
-  return this.getCopayerId(0,prefix);
+PublicKeyRing.prototype.myCopayerId = function(i) {
+  return this.getCopayerId(0);
 };
 
 PublicKeyRing.prototype.registeredCopayers = function () {
diff --git a/js/models/core/Wallet.js b/js/models/core/Wallet.js
index 0e1d12348..fdbfe36ee 100644
--- a/js/models/core/Wallet.js
+++ b/js/models/core/Wallet.js
@@ -169,9 +169,10 @@ Wallet.prototype.netStart = function() {
 
   var myId = self.getMyCopayerId();
   var startOpts = { 
-    copayerId: myId
+    copayerId: myId,
+    signingKeyHex: self.privateKey.getSigningKey(),
   };
-  net.start(function() {
+  net.start(startOpts, function() {
     self.emit('created');
     for (var i=0; i<self.publicKeyRing.registeredCopayers(); i++) {
       var otherId = self.getCopayerId(i);
@@ -184,7 +185,7 @@ Wallet.prototype.netStart = function() {
     }
     self.emit('refresh');
     }
-  }, startOpts);
+  });
 };
 
 Wallet.prototype.store = function(isSync) {
diff --git a/js/models/core/WalletFactory.js b/js/models/core/WalletFactory.js
index d0e1bd014..d43620b35 100644
--- a/js/models/core/WalletFactory.js
+++ b/js/models/core/WalletFactory.js
@@ -146,8 +146,8 @@ WalletFactory.prototype.joinCreateSession = function(copayerId, cb) {
   var privateKey = new PrivateKey({ networkName: this.networkName });
   this.log('\t### PrivateKey Initialized');
   self.network.setCopayerId(privateKey.getId());
-
-  self.network.start(function() {
+  self.network.setSigningKey(privateKey.getSigningKey());
+  self.network.start({}, function() {
     self.network.connectTo(copayerId);
     self.network.on('data', function(sender, data) {
       if (data.type ==='walletId') {
diff --git a/js/models/network/WebRTC.js b/js/models/network/WebRTC.js
index b9398ef71..24fbeb3ac 100644
--- a/js/models/network/WebRTC.js
+++ b/js/models/network/WebRTC.js
@@ -3,6 +3,7 @@ var imports     = require('soop').imports();
 var EventEmitter= imports.EventEmitter || require('events').EventEmitter;
 var bitcore     = require('bitcore');
 var util        = bitcore.util;
+var Key         = bitcore.Key;
 
 /*
  * Emits
@@ -102,10 +103,10 @@ console.log('[WebRTC.js.99:arrayDiff:]',arrayDiff); //TODO
   });
 };
 
-Network.prototype._sendCopayerId = function(copayerId) {
-  console.log('#### SENDING COPAYERID TO TO ', copayerId);
+Network.prototype._sendHello = function(copayerId) {
+  console.log('#### SENDING HELLO TO ', copayerId);
   this.send(copayerId, {
-    type: 'copayerId',
+    type: 'hello',
     copayerId: this.copayerId,
   });
 };
@@ -133,45 +134,63 @@ Network.prototype._addCopayer = function(copayerId, isInbound) {
 };
 
 Network.prototype._onData = function(data, isInbound, peerId) {
-  var obj;
+  var sig, payload;
   try { 
-    obj = JSON.parse(data);
+    var dataObj = JSON.parse(data);
+    sig = dataObj.sig;
+    payload= dataObj.payload;
+
   } catch (e) {
     console.log('### ERROR ON DATA: "%s" ', data, isInbound, e); 
     return;
   };
-  console.log('### RECEIVED TYPE: %s FROM %s', obj.data.type, obj.sender, obj.data); 
+
+  console.log('### RECEIVED INBOUND?:%s TYPE: %s FROM %s: sig:%s', 
+              isInbound, payload.type, peerId, sig, payload); 
   var self=this;
 
-  if(obj.data.type === 'copayerId') {
-      if (this.peerFromCopayer(obj.data.copayerId) === peerId) {
-        console.log('#### Peer sent the right copayerId. Setting it up.'); //TODO
-        this._addCopayer(obj.data.copayerId, isInbound);
-        this._notifyNetworkChange( isInbound ? obj.data.copayerId : null);
-        this.emit('open');
-      }
-      else {
-        console.log('### RECEIVED WRONG COPAYER ID FROM:', peerId); //TODO
-      }
+  // TODO _func
+  if(payload.type === 'hello') {
+    var thisSig = this._sign(payload, this.copayerId);
+    if (thisSig !== sig) {
+      console.log('#### Peer sent WRONG hello. Closing connection.');
       return;
+    }
+    console.log('#### Peer sent signed hello. Setting it up.'); //TODO
+    this._addCopayer(payload.copayerId, isInbound);
+    this._notifyNetworkChange( isInbound ? payload.copayerId : null);
+    this.emit('open');
+    return;
   }
 
   if (!this.copayerForPeer[peerId]) {
     console.log('### Discarting message from unknow peer: ', peerId); //TODO
     return;
   }
+
+  // check sig
+  if (this.copayerForPeer[peerId]) {
+    var copayerIdBuf = new Buffer(this.copayerForPeer[peerId],'hex');
+    if (!bitcore.Message.verifyWithPubKey( copayerIdBuf, JSON.stringify(payload), 
+      new Buffer(sig,'hex'))) {
+
+      console.log('[WebRTC.js.152] SIGNATURE VERIFICATION FAILED!!'); //TODO
+      // TODO close connection
+      return;
+    }
+  }
   
-  switch(obj.data.type) {
+  switch(payload.type) {
     case 'copayers':
       this._addCopayer(this.copayerForPeer[peerId], false);
-      this._connectToCopayers(obj.data.copayers);
+      this._connectToCopayers(payload.copayers);
       this._notifyNetworkChange();
       break;
     case 'disconnect':
-      this._onClose(obj.sender);
+      this._onClose(peerId);
       break;
     default:
-      this.emit('data', self.copayerForPeer[obj.sender], obj.data, isInbound);
+      this.emit('data', self.copayerForPeer[peerId], payload, isInbound);
   }
 };
 
@@ -193,12 +212,12 @@ Network.prototype._setupConnectionHandlers = function(dataConn, isInbound) {
 
       self.connections[dataConn.peer] = dataConn;
 
-      console.log('### DATA CONNECTION READY: ADDING PEER: %s (inbound: %s)',
+      console.log('### DATA CONNECTION READY: %s (inbound: %s) AUTHENTICATING...',
         dataConn.peer, isInbound);
 
-      // The outbount send its copayerID
+      // The connection peer send hello (with signature)
       if(!isInbound) 
-        self._sendCopayerId(self.copayerForPeer[dataConn.peer]);      
+        self._sendHello(self.copayerForPeer[dataConn.peer]);      
     }
   });
 
@@ -272,24 +291,39 @@ Network.prototype.setCopayerId = function(copayerId) {
   if (this.started) {
     throw new Error ('network already started: can not change peerId')
   }
+console.log('[WebRTC.js.295] SETING COPAYER ID:'  + copayerId); //TODO
   this.copayerId = copayerId;
+  this.copayerIdBuf = new Buffer(copayerId,'hex');
   this.peerId = this.peerFromCopayer(this.copayerId);
   this._addCopayerMap(this.peerId,copayerId);
 };
 
+
+Network.prototype.setSigningKey = function(keyHex) {
+  if (this.started || this.signingKey) {
+    throw new Error ('network already started or key assigned: can not change key')
+  }
+  var k = new Key();
+  k.private = new Buffer(keyHex,'hex');
+  k.regenerateSync();
+  this.signingKey = k;
+};
+
 Network.prototype.peerFromCopayer = function(hex) {
   return util.sha256(new Buffer(hex,'hex')).toString('hex');
 };
 
-Network.prototype.start = function(openCallback, opts) {
+Network.prototype.start = function(opts, openCallback) {
   opts = opts || {};
   var self = this;
   if (this.started)  return openCallback();
-
   opts.connectedPeers = opts.connectedPeers || [];
 
+  if (!this.copayerId) 
+    this.setCopayerId(opts.copayerId);
+  if (!this.signingKey) 
+    this.setSigningKey(opts.signingKeyHex);
 
-  this.setCopayerId(this.copayerId || opts.copayerId);
   this.peer = new Peer(this.peerId, this.opts);
   this._setupPeerHandlers(openCallback);
   for (var i = 0; i<opts.connectedPeers.length; i++) {
@@ -300,15 +334,39 @@ Network.prototype.start = function(openCallback, opts) {
 console.log('[WebRTC.js.237] started TRUE'); //TODO
 };
 
-Network.prototype._sendToOne = function(copayerId, data, cb) {
 
+Network.prototype._sign = function(payload, copayerId) {
+  var ret='';
+  var str = JSON.stringify(payload);
+  if (payload.type ==='hello') {
+console.log('[WebRTC.js.331] SIGNING WITH HMAC:', copayerId); //TODO
+    ret = CryptoJS.enc.Base64.stringify(
+      CryptoJS.HmacSHA256(
+      str, 
+      copayerId
+    ));
+  }
+  else {
+    if (!this.signingKey)
+      throw new Error ('no key to sign messages :(');
+
+console.log('[WebRTC.js.341] SIGNING WITH ECDSA'); //TODO
+    ret = bitcore.Message.sign(
+      str, 
+      this.signingKey
+    ).toString('hex');
+  }
+  return ret;
+};
+
+Network.prototype._sendToOne = function(copayerId, payload, cb) {
   var peerId = this.peerFromCopayer(copayerId);
   if (peerId !== this.peerId) {
     var dataConn = this.connections[peerId];
     if (dataConn) {
       var str = JSON.stringify({
-        sender: this.peerId,
-        data: data
+        sig: this._sign(payload, copayerId),
+        payload: payload 
       });
       dataConn.send(str);
     }
@@ -319,24 +377,24 @@ console.log('[WebRTC.js.255] WARN: NO CONNECTION TO:', peerId); //TODO
   if (typeof cb === 'function') cb();
 };
 
-Network.prototype.send = function(copayerIds, data, cb) {
+Network.prototype.send = function(copayerIds, payload, cb) {
   var self=this;
   if (!copayerIds) {
     copayerIds = this.connectedCopayers();
-    data.isBroadcast = 1;
+    payload.isBroadcast = 1;
   }
 
   if (Array.isArray(copayerIds)) {
     var l = copayerIds.length;
     var i = 0;
     copayerIds.forEach(function(copayerId) {
-      self._sendToOne(copayerId, data, function () {
+      self._sendToOne(copayerId, payload, function () {
         if (++i === l && typeof cb === 'function') cb();
       });
     });
   }
   else if (typeof copayerIds === 'string')
-    self._sendToOne(copayerIds, data, cb);
+    self._sendToOne(copayerIds, payload, cb);
 };
 
 Network.prototype.connectTo = function(copayerId) {
diff --git a/test/test.PrivateKey.js b/test/test.PrivateKey.js
index 9eafd5794..71ae071be 100644
--- a/test/test.PrivateKey.js
+++ b/test/test.PrivateKey.js
@@ -70,7 +70,7 @@ describe('PrivateKey model', function() {
   it('should calculate .id', function () {
     var w1 = new PrivateKey(config);
     should.exist(w1.getId());
-    w1.getId().length.should.equal(32);
+    w1.getId().length.should.equal(66);
   });
   it('fromObj toObj roundtrip', function () {
     var w1 = new PrivateKey(config);
diff --git a/test/test.PublicKeyRing.js b/test/test.PublicKeyRing.js
index c3701cb8b..76c0ff169 100644
--- a/test/test.PublicKeyRing.js
+++ b/test/test.PublicKeyRing.js
@@ -228,7 +228,7 @@ describe('PublicKeyRing model', function() {
       networkName: 'livenet',
     });
     wx.addCopayer();
-    (function() { w.merge(wx, true);}).should.throw();
+    (function() { w.merge(wx);}).should.throw();
 
 
   });