diff --git a/chatdialog.cpp b/chatdialog.cpp
index 58bdd90..57de04e 100644
--- a/chatdialog.cpp
+++ b/chatdialog.cpp
@@ -6,6 +6,8 @@
 #include <QTimer>
 #include <QMetaType>
 #include <QMessageBox>
+#include <boost/random/random_device.hpp>
+#include <boost/random/uniform_int_distribution.hpp>
 
 #define BROADCAST_PREFIX_FOR_SYNC_DEMO "/ndn/broadcast/sync-demo"
 
@@ -282,6 +284,21 @@
   msg.set_type(SyncDemo::ChatMessage::CHAT);
 }
 
+static std::string chars("qwertyuiopasdfghjklzxcvbnmQWERTYUIOPASDFGHJKLZXCVBNM0123456789");
+
+QString
+ChatDialog::getRandomString()
+{
+  std::string randStr;
+  boost::random::random_device rng;
+  boost::random::uniform_int_distribution<> index_dist(0, chars.size() - 1);
+  for (int i = 0; i < 10; i ++)
+  {
+    randStr += chars[index_dist(rng)];
+  }
+  return randStr.c_str();
+}
+
 bool
 ChatDialog::readSettings()
 {
@@ -390,7 +407,7 @@
     needWrite = true;
   }
   if (!prefix.isEmpty() && prefix != m_user.getPrefix()) {
-    m_user.setPrefix(prefix);
+    m_user.setPrefix(prefix + "/" + getRandomString());
     needWrite = true;
     // TODO: set the previous prefix as left?
   }
diff --git a/chatdialog.h b/chatdialog.h
index 116e20e..0d4984a 100644
--- a/chatdialog.h
+++ b/chatdialog.h
@@ -39,6 +39,7 @@
   void processData(QString name, const char *buf, size_t len);
 
 private:
+  QString getRandomString();
   void formChatMessage(const QString &text, SyncDemo::ChatMessage &msg);
   bool readSettings();
   void writeSettings();
diff --git a/digesttreescene.cpp b/digesttreescene.cpp
index 50d170b..b0b3d7c 100644
--- a/digesttreescene.cpp
+++ b/digesttreescene.cpp
@@ -95,7 +95,7 @@
 #ifdef __DEBUG
   else 
   {
-    std::cout << "Couldn't find prefix, let's check"<< std::endl;
+    std::cout << "Couldn't find prefix, " << prefix.toStdString() << ": let's check"<< std::endl;
     Roster_iterator ii = m_roster.begin();
     while (ii != m_roster.end())
     {
diff --git a/sync-demo.pro b/sync-demo.pro
index f65fbdd..c82c20b 100644
--- a/sync-demo.pro
+++ b/sync-demo.pro
@@ -20,7 +20,7 @@
 
 QMAKE_CXXFLAGS *= -g 
 QMAKE_CFLAGS *= -g 
-LIBS += -lboost_system-mt
+LIBS += -lboost_system-mt -lboost_random
 
 CONFIG += console