diff --git a/ws2012/P2P/uebungen/11/src/node/ChunkIdentifier.java b/ws2012/P2P/uebungen/11/src/node/ChunkIdentifier.java
new file mode 100644
index 00000000..3bc9143f
--- /dev/null
+++ b/ws2012/P2P/uebungen/11/src/node/ChunkIdentifier.java
@@ -0,0 +1,36 @@
+package node;
+
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+
+public class ChunkIdentifier extends Identifier {
+	
+	private String chunkID;
+	private FileIdentifier fileID;
+
+	public ChunkIdentifier(int size, byte[] bytes, FileIdentifier fileID, String chunkID) {
+		super(size, bytes);
+		
+		this.fileID = fileID;
+		
+		//calculate SHA-256 Hash of chunckID
+		try {
+			MessageDigest md = MessageDigest.getInstance("SHA-256");
+			md.update(chunkID.getBytes());
+			this.chunkID = md.digest().toString();
+		} catch (NoSuchAlgorithmException e) {
+			// TODO Auto-generated catch block
+			e.printStackTrace();
+		}
+		
+	}
+	
+	public String getChunkID() {
+		return this.chunkID;
+	}
+	
+	public FileIdentifier getFileID(){
+		return this.fileID;
+	}
+
+}
diff --git a/ws2012/P2P/uebungen/11/src/node/FileIdentifier.java b/ws2012/P2P/uebungen/11/src/node/FileIdentifier.java
index fdcb8be7..bd5cdef1 100644
--- a/ws2012/P2P/uebungen/11/src/node/FileIdentifier.java
+++ b/ws2012/P2P/uebungen/11/src/node/FileIdentifier.java
@@ -1,16 +1,28 @@
 package node;
 
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+
 public class FileIdentifier extends Identifier {
 	
-	private String key;
+	private String fileID;
 
-	public FileIdentifier(int size, byte[] bytes, String key) {
+	public FileIdentifier(int size, byte[] bytes, String fileID) {
 		super(size, bytes);
-		this.key = key;
-		// TODO: key muss noch gehasht werden
+		
+		//calculate SHA-256 Hash of key
+		try {
+			MessageDigest md = MessageDigest.getInstance("SHA-256");
+			md.update(fileID.getBytes());
+			this.fileID = md.digest().toString();
+		} catch (NoSuchAlgorithmException e) {
+			// TODO Auto-generated catch block
+			e.printStackTrace();
+		}
+		
 	}
 	
 	public String getKey() {
-		return this.key;
+		return this.fileID;
 	}
 }
diff --git a/ws2012/P2P/uebungen/11/src/node/Node.java b/ws2012/P2P/uebungen/11/src/node/Node.java
index 6c1c8d08..91e69573 100644
--- a/ws2012/P2P/uebungen/11/src/node/Node.java
+++ b/ws2012/P2P/uebungen/11/src/node/Node.java
@@ -181,6 +181,15 @@ public class Node {
                     new Object[] { fileID, receiver });
         }
     }
+    
+    public void sendData(NodeIdentifier receiver, FileIdentifier fileID, ChunkIdentifier chunckID){
+    	
+    	//TODO: implement
+    	
+    	
+    	
+    }
+    
 
     public void sendPing(NodeIdentifier receiver, MessageCallback cb) {
         boolean successful = send(receiver, MessageType.PING, null, true, cb);
diff --git a/ws2012/P2P/uebungen/11/src/node/UDPHandler.java b/ws2012/P2P/uebungen/11/src/node/UDPHandler.java
index 9ccb4c98..b5b813eb 100644
--- a/ws2012/P2P/uebungen/11/src/node/UDPHandler.java
+++ b/ws2012/P2P/uebungen/11/src/node/UDPHandler.java
@@ -136,6 +136,10 @@ public class UDPHandler implements Runnable {
                         break;
                     case MessageType.DATA:
                         //TODO implemnt
+                    	
+                    	//rpcID splitten ? -> [0] fileID, [1] partID ?!?!?!
+                    	receiveData(fromID, fileID, partID);
+                    	
                         LOGGER.log(Level.INFO, "Received DATA from {0}",
                                 new Object[] { from.toString() });
                         break;
@@ -217,6 +221,12 @@ public class UDPHandler implements Runnable {
     
     private void receiveStore(NodeIdentifier fromID, Identifier rpc_id) {
     	Identifier fileID = getIDFromBuffer();
+
+    	//TODO Cast geht an dieser stelle nicht, getIDFromBuffer() müsste man für
+    	// FileID implementieren.
+    	
+    	// warum speichern wir nicht einfach die rpc_od ???
+    	fileID = rpc_id;
     	
     	System.out.println("Received store from " + fromID.toString());