diff --git a/FPE/Identity.py b/FPE/Identity.py
index 26cc58b..dfad666 100644
--- a/FPE/Identity.py
+++ b/FPE/Identity.py
@@ -179,7 +179,6 @@ class Identity:
 		if self.pub != None:
 			chunksize = (Identity.KEYSIZE-Identity.PADDINGSIZE)/8
 			chunks = int(math.ceil(len(plaintext)/(float(chunksize))))
-			# TODO: Remove debug output print("Plaintext size is "+str(len(plaintext))+", with "+str(chunks)+" chunks")
 
 			ciphertext = "";
 			for chunk in range(chunks):
@@ -187,8 +186,6 @@ class Identity:
 				end = (chunk+1)*chunksize
 				if (chunk+1)*chunksize > len(plaintext):
 					end = len(plaintext)
-
-				# TODO: Remove debug output print("Processing chunk "+str(chunk+1)+" of "+str(chunks)+". Starting at "+str(start)+" and stopping at "+str(end)+". The length is "+str(len(plaintext[start:end])))
 				
 				ciphertext += self.pub.encrypt(
 					plaintext[start:end],
@@ -198,7 +195,6 @@ class Identity:
 						label=None
 					)
 				)
-			# TODO: Remove debug output print("Plaintext encrypted, ciphertext length is "+str(len(ciphertext))+" bytes.")
 			return ciphertext
 		else:
 			raise KeyError("Encryption failed because identity does not hold a public key")
diff --git a/FPE/Interfaces/SerialInterface.py b/FPE/Interfaces/SerialInterface.py
index dfe2699..cc488ae 100755
--- a/FPE/Interfaces/SerialInterface.py
+++ b/FPE/Interfaces/SerialInterface.py
@@ -9,7 +9,6 @@ import FPE
 
 class SerialInterface(Interface):
 	MAX_CHUNK = 32768
-	TIMEOUT_SECONDS = 1.0
 
 	owner    = None
 	port     = None
diff --git a/FPE/Interfaces/UdpInterface.py b/FPE/Interfaces/UdpInterface.py
index 52472d2..d0359bb 100755
--- a/FPE/Interfaces/UdpInterface.py
+++ b/FPE/Interfaces/UdpInterface.py
@@ -37,13 +37,9 @@ class UdpInterface(Interface):
 
 
     def processIncoming(self, data):
-        # TODO: remove
-        #FPE.log("IN: "+FPE.prettyhexrep(data))
         self.owner.inbound(data)
 
     def processOutgoing(self,data):
-        # TODO: remove
-        #FPE.log("OUT: "+FPE.prettyhexrep(" "+data))
         udp_socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
         udp_socket.setsockopt(socket.SOL_SOCKET, socket.SO_BROADCAST, 1)
         udp_socket.sendto(data, (self.forward_ip, self.forward_port))
@@ -57,7 +53,5 @@ class UdpInterfaceHandler(SocketServer.BaseRequestHandler):
 
     def handle(self):
         if (UdpInterfaceHandler.interface != None):
-            # TODO: remove
-            #FPE.log("Datagram contents: "+FPE.prettyhexrep(self.request[0]))
             data = self.request[0]
             UdpInterfaceHandler.interface.processIncoming(data)
\ No newline at end of file
diff --git a/FPE/Utilities/Echo.py b/FPE/Utilities/Echo.py
index 2d662e8..2f6a192 100644
--- a/FPE/Utilities/Echo.py
+++ b/FPE/Utilities/Echo.py
@@ -179,31 +179,55 @@ def client(destination_hexhash, configpath):
 			# user to wait for an announce to arrive.
 			FPE.log("Destination is not yet known. Wait for an announce to arrive.")
 
+# This method is called when our reply destination
+# receives a proof packet.
 def clientProofCallback(proof_packet):
+	# We save the current time so we can calculate
+	# round-trip time for the packet
 	now = time.time()
+
+	# Let's look through our list of sent requests,
+	# and see if we can find one that matches the
+	# proof we just received.
 	for unproven_packet in sent_requests:
-		if unproven_packet.packet_hash == proof_packet.data[:32]:
-			if unproven_packet.validateProofPacket(proof_packet):
-				rtt = now - unproven_packet.sent_at
-				if (rtt >= 1):
-					rtt = round(rtt, 3)
-					rttstring = str(rtt)+" seconds"
+		try:
+			# Check that the proof hash matches the
+			# hash of the packet we sent earlier
+			if unproven_packet.packet_hash == proof_packet.data[:32]:
+				# We need to actually calidate the proof.
+				# This is simply done by calling the
+				# validateProofPacket method on the packet
+				# we sent earlier.
+				if unproven_packet.validateProofPacket(proof_packet):
+					# If the proof is valid, we will calculate
+					# the round-trip time, and inform the user.
+					rtt = now - unproven_packet.sent_at
+					if (rtt >= 1):
+						rtt = round(rtt, 3)
+						rttstring = str(rtt)+" seconds"
+					else:
+						rtt = round(rtt*1000, 3)
+						rttstring = str(rtt)+" milliseconds"
+					
+					FPE.log(
+						"Valid echo reply, proved by "+FPE.prettyhexrep(unproven_packet.destination.hash)+
+						", round-trip time was "+rttstring
+						)
+					# Perform some cleanup
+					sent_requests.remove(unproven_packet)
+					del unproven_packet
 				else:
-					rtt = round(rtt*1000, 3)
-					rttstring = str(rtt)+" milliseconds"
-				
-				FPE.log(
-					"Valid echo reply, proved by "+FPE.prettyhexrep(unproven_packet.destination.hash)+
-					", round-trip time was "+rttstring
-					)
-				sent_requests.remove(unproven_packet)
-				del unproven_packet
-			else:
-				FPE.log("Proof invalid")
+					# If the proof was invalid, we inform 
+					# the user of this.
+					FPE.log("Echo reply received, but proof was invalid")
+		except:
+			FPE.log("Proof packet received, but packet contained invalid or unparsable data")
 
 
 
 if __name__ == "__main__":
+	# Set up command line arguments and start
+	# the selected program mode.
 	try:
 		parser = argparse.ArgumentParser(description="Simple echo server and client utility")
 		parser.add_argument("-s", "--server", action="store_true", help="wait for incoming packets from clients")