diff --git a/gntp.py b/gntp.py
index a49ce64..e370672 100644
--- a/gntp.py
+++ b/gntp.py
@@ -38,6 +38,29 @@ def set_password(self,password,encryptAlgo='MD5'):
 		self.info['keyHashAlgorithmID'] = encryptAlgo.upper()
 		self.info['keyHash'] = keyHash.upper()
 		self.info['salt'] = salt.upper()
+	def _decode_hex(self,value):
+		result = ''
+		for i in range(0,len(value),2):
+			tmp = int(value[i:i+2],16)
+			result += chr(tmp)
+		return result
+	def validate_password(self):
+		if not self.info.get('keyHash',None):
+			return True
+		if not self.password:
+			raise GNTPParseError('Missing Password')
+		
+		password = self.password.encode('utf8')
+		saltHash = self._decode_hex(self.info['salt'])
+		
+		keyBasis = password+saltHash
+		key = hashlib.md5(keyBasis).digest()
+		keyHash = hashlib.md5(key).hexdigest()
+		
+		if not keyHash.upper() == self.info['keyHash'].upper():
+			raise GNTPParseError('Invalid Hash')
+		return True
+		
 		
 	def format_info(self):
 		info = u'GNTP/%s %s'%(
@@ -75,10 +98,11 @@ def add_header(self,key,value):
 		self.headers[key] = value
 
 class GNTPRegister(_GNTPBase):
-	def __init__(self,data=None):
+	def __init__(self,data=None,password=None):
 		_GNTPBase.__init__(self,'REGISTER')
 		self.headers	= {}
 		self.notifications = []
+		self.password = password
 		self.requiredHeaders = [
 			'Application-Name',
 			'Notifications-Count'
@@ -103,6 +127,7 @@ def decode(self,data):
 		self.raw = data
 		parts = self.raw.split('\r\n\r\n')
 		self.info = self.parse_info(data)
+		self.validate_password()
 		self.headers = self.parse_dict(parts[0])
 		
 		if len(parts) > 1:
@@ -143,10 +168,11 @@ def __str__(self):
 		return self.encode()
 
 class GNTPNotice(_GNTPBase):
-	def __init__(self,data=None,app=None,name=None,title=None):
+	def __init__(self,data=None,app=None,name=None,title=None,password=None):
 		_GNTPBase.__init__(self,'NOTIFY')
 		self.headers	= {}
 		self.resources	= {}
+		self.password = password
 		self.requiredHeaders = [
 			'Application-Name',
 			'Notification-Name',
@@ -169,6 +195,7 @@ def decode(self,data):
 		self.raw = data
 		parts = self.raw.split('\r\n\r\n')
 		self.info = self.parse_info(data)
+		self.validate_password()
 		self.headers = self.parse_dict(parts[0])
 		if len(parts) > 1:
 			print 'Extra parts'
@@ -235,15 +262,15 @@ def __init__(self,data=None):
 		if data:
 			self.decode(data)
 
-def parse_gntp(data,debug=False):
+def parse_gntp(data,password=None,debug=False):
 	match = re.match('GNTP/(?P<version>\d+\.\d+) (?P<messagetype>REGISTER|NOTIFY|\-OK|\-ERROR)',data,re.IGNORECASE)
 	if not match:
 		raise GNTPParseError('INVALID_GNTP_INFO')
 	info = match.groupdict()
 	if info['messagetype'] == 'REGISTER':
-		return GNTPRegister(data)
-	elif info['messagetype'] == 'NOTICE':
-		return GNTPNotice(data)
+		return GNTPRegister(data,password=password)
+	elif info['messagetype'] == 'NOTIFY':
+		return GNTPNotice(data,password=password)
 	elif info['messagetype'] == '-OK':
 		return GNTPResponse(data)
 	elif info['messagetype'] == '-ERROR':
@@ -252,4 +279,5 @@ def parse_gntp(data,debug=False):
 		print '----'
 		print self.data
 		print '----'
+	print info
 	raise GNTPParseError('INVALID_GNTP_MESSAGE')
diff --git a/local.py b/local.py
index 4b4ed5f..5d8f3e2 100644
--- a/local.py
+++ b/local.py
@@ -1,6 +1,11 @@
 import gntp
 import Growl
 
+GNTPParseError = gntp.GNTPParseError
+GNTPOK = gntp.GNTPOK
+GNTPError = gntp.GNTPError
+parse_gntp = gntp.parse_gntp
+
 class GNTPRegister(gntp.GNTPRegister):
 	def send(self):
 		print 'Sending Local Registration'
diff --git a/server.py b/server.py
index 6661c02..347c18e 100644
--- a/server.py
+++ b/server.py
@@ -22,15 +22,15 @@ def handle(self):
 		self.data = self.read()
 		
 		try:
-			message = parse_gntp(self.data)
+			message = gntp.parse_gntp(self.data,self.server.growl_password)
 			message.send()
 			
-			response = GNTPOK()
+			response = gntp.GNTPOK()
 			self.write(response.encode())
-		except GNTPError:
+		except gntp.GNTPError:
 			if self.server.growl_debug:
 				traceback.print_exc()
-			response = GNTPError()
+			response = gntp.GNTPError()
 			self.write(response.encode())
 		
 if __name__ == "__main__":
@@ -40,16 +40,17 @@ def handle(self):
 	parser.add_option("-p","--port",dest="port",help="port to listen on",type="int",default=23053)
 	parser.add_option("-r","--regrowl",dest='regrowl',help="ReGrowl on local OSX machine",action="store_true",default=False)
 	parser.add_option("-d","--debug",dest='debug',help="Print raw growl packets",action="store_true",default=False)
+	parser.add_option("-P","--password",dest='password',help="Network password",default=None)
 	(options, args) = parser.parse_args()
 	
 	if options.regrowl:
-		from local import GNTPRegister,GNTPNotice
-		from gntp import GNTPParseError,GNTPOK,GNTPError,parse_gntp
+		import local as gntp
 	else:
-		from gntp import *
+		import gntp
 	
 	server = GNTPServer((options.host, options.port), GNTPHandler)
 	server.growl_debug = options.debug
+	server.growl_password = options.password
 	
 	sa = server.socket.getsockname()
 	print "Listening for GNTP on", sa[0], "port", sa[1], "..."