diff --git a/core/src/main/java/com.riverssen.p2p4j/CryptographicScheme.java b/core/src/main/java/com.riverssen.p2p4j/CryptographicScheme.java
new file mode 100644
index 0000000..8e639ec
--- /dev/null
+++ b/core/src/main/java/com.riverssen.p2p4j/CryptographicScheme.java
@@ -0,0 +1,6 @@
+package com.riverssen.p2p4j;
+
+public abstract class CryptographicScheme {
+    public abstract byte[] encrypt(Packet packet);
+    public abstract byte[] decrypt(byte[] bytes);
+}
diff --git a/core/src/main/java/com.riverssen.p2p4j/DefaultScheme.java b/core/src/main/java/com.riverssen.p2p4j/DefaultScheme.java
new file mode 100644
index 0000000..cfc6022
--- /dev/null
+++ b/core/src/main/java/com.riverssen.p2p4j/DefaultScheme.java
@@ -0,0 +1,13 @@
+package com.riverssen.p2p4j;
+
+public class DefaultScheme extends CryptographicScheme {
+    @Override
+    public byte[] encrypt(Packet packet) {
+        return packet.getBytes();
+    }
+
+    @Override
+    public byte[] decrypt(byte[] bytes) {
+        return bytes;
+    }
+}
diff --git a/core/src/main/java/com.riverssen.p2p4j/Node.java b/core/src/main/java/com.riverssen.p2p4j/Node.java
index 40da419..78685d4 100644
--- a/core/src/main/java/com.riverssen.p2p4j/Node.java
+++ b/core/src/main/java/com.riverssen.p2p4j/Node.java
@@ -79,14 +79,10 @@ protected boolean sendMessage(Packet packet)
             if (packet.getSize() > server.getParameters().getMaxBytesSend())
                 return false;
 
-            /**
-             * Check that the packet has not been sent
-             * before.
-             *
-             * This is implementation specific.
-             */
-            if (nodeID.screen(packet.getHashCode()))
-                return false;
+            byte encodedBytes[] = nodeID.getScheme().encrypt(packet);
+            dataOutputStream.writeInt(encodedBytes.length);
+            dataOutputStream.write(encodedBytes);
+            dataOutputStream.flush();
 
             /**
              * Cache the hash of this packet to insure
@@ -95,10 +91,6 @@ protected boolean sendMessage(Packet packet)
              */
             nodeID.cache(packet.getHashCode());
 
-            dataOutputStream.writeInt(packet.getSize());
-            packet.write(dataOutputStream);
-            dataOutputStream.flush();
-
             return true;
         } catch (IOException e) {
         }
@@ -107,7 +99,17 @@ protected boolean sendMessage(Packet packet)
     }
 
     public boolean send(Packet packet) {
-        if (connected.get()) return messages.add(packet);
+        if (connected.get()) {
+            /**
+             * Check that the packet has not been sent
+             * before.
+             *
+             * This is implementation specific.
+             */
+            if (nodeID.screen(packet.getHashCode()))
+                return false;
+            return messages.add(packet);
+        }
         return false;
     }
 
diff --git a/core/src/main/java/com.riverssen.p2p4j/NodeID.java b/core/src/main/java/com.riverssen.p2p4j/NodeID.java
index 2eb9995..2e40125 100644
--- a/core/src/main/java/com.riverssen.p2p4j/NodeID.java
+++ b/core/src/main/java/com.riverssen.p2p4j/NodeID.java
@@ -17,6 +17,8 @@ public abstract class NodeID {
     public abstract boolean screen(byte[] object);
     public abstract void cache(byte[] object);
 
+    public abstract CryptographicScheme getScheme();
+
     @Override
     public String toString() {
         return getAddress() + ":" + getPort();
diff --git a/core/src/main/java/com.riverssen.p2p4j/Packet.java b/core/src/main/java/com.riverssen.p2p4j/Packet.java
index 5cd2302..cd64fcf 100644
--- a/core/src/main/java/com.riverssen.p2p4j/Packet.java
+++ b/core/src/main/java/com.riverssen.p2p4j/Packet.java
@@ -19,4 +19,5 @@ public abstract class Packet {
     public abstract void write(DataOutputStream dataOutputStream) throws IOException;
 
     public abstract byte[] getHashCode();
+    public abstract byte[] getBytes();
 }
diff --git a/core/src/test/java/tests/GenericPacket.java b/core/src/test/java/tests/GenericPacket.java
index f710932..23d99f4 100644
--- a/core/src/test/java/tests/GenericPacket.java
+++ b/core/src/test/java/tests/GenericPacket.java
@@ -47,4 +47,9 @@ public void write(DataOutputStream dataOutputStream) throws IOException {
     public byte[] getHashCode() {
         return new byte[1];
     }
+
+    @Override
+    public byte[] getBytes() {
+        return getBuffer().array();
+    }
 }
diff --git a/core/src/test/java/tests/Main.java b/core/src/test/java/tests/Main.java
index 1f7af15..71d2182 100644
--- a/core/src/test/java/tests/Main.java
+++ b/core/src/test/java/tests/Main.java
@@ -11,6 +11,8 @@
 import com.riverssen.p2p4j.ServerParameters;
 import com.riverssen.p2p4j.Descriptor;
 import com.riverssen.p2p4j.Packet;
+import com.riverssen.p2p4j.CryptographicScheme;
+import com.riverssen.p2p4j.DefaultScheme;
 
 import java.io.DataOutputStream;
 import java.io.IOException;
@@ -92,9 +94,9 @@ public static void createServerB(String name, int port) throws IOException {
 
                 message.send(theNode);
                 System.out.println(name + " sent " + message.getPacket().getSize());
-                ResponsePacket<String, ResponseCode> response1 = request1.<String, ResponseCode>sendGetReply(theNode, 1500);
+                ResponsePacket<String, ResponseCode> response1 = request1.<String, ResponseCode>sendGetReply(theNode, 10000);
                 System.out.println(name + " sent " + request1.getPacket().getSize() + " " + request1.getPacket().getSerialNumber());
-                ResponsePacket<Integer, ResponseCode> response2 = request2.<Integer, ResponseCode>sendGetReply(theNode, 1500);
+                ResponsePacket<Integer, ResponseCode> response2 = request2.<Integer, ResponseCode>sendGetReply(theNode, 10000);
                 System.out.println(name + " sent " + request2.getPacket().getSize() + " " + request2.getPacket().getSerialNumber());
 
                 System.out.println(name + ".. response1: " + response1);
@@ -203,12 +205,14 @@ public static class NodeIDImpl extends NodeID {
         private int spam = 0;
         private InetAddress address;
         private int port;
+        private CryptographicScheme scheme;
 
         public NodeIDImpl(InetAddress address, int port)
         {
             this.address = address;
             this.port = port;
             this.setShouldBan(false);
+            this.scheme = new DefaultScheme();
         }
 
         @Override
@@ -256,6 +260,11 @@ public boolean screen(byte[] object) {
         @Override
         public void cache(byte[] object) {
         }
+
+        @Override
+        public CryptographicScheme getScheme() {
+            return scheme;
+        }
     }
 
     public static enum PacketType {
@@ -320,6 +329,11 @@ public void write(DataOutputStream dataOutputStream) throws IOException {
         public byte[] getHashCode() {
             return new byte[1];
         }
+
+        @Override
+        public byte[] getBytes() {
+            return getBuffer().array();
+        }
     }
 
     public static class GenericResponsePacket extends Packet {
@@ -383,6 +397,11 @@ public void write(DataOutputStream dataOutputStream) throws IOException {
         public byte[] getHashCode() {
             return new byte[1];
         }
+
+        @Override
+        public byte[] getBytes() {
+            return getBuffer().array();
+        }
     }
 
     public static class StringMessage extends Message {