diff --git a/lam/lib/security.inc b/lam/lib/security.inc
new file mode 100644
index 00000000..ed8d3ac7
--- /dev/null
+++ b/lam/lib/security.inc
@@ -0,0 +1,86 @@
+<?php
+/*
+$Id$
+
+  This code is part of LDAP Account Manager (http://www.sourceforge.net/projects/lam)
+  Copyright (C) 2006  Roland Gruber
+
+  This program is free software; you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation; either version 2 of the License, or
+  (at your option) any later version.
+
+  This program is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program; if not, write to the Free Software
+  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+
+*/
+
+/**
+* This file includes functions to perform several security checks on each page load.
+*
+* @package lib
+* @author Roland Gruber
+*/
+
+/**
+ * Starts a session and checks the environment.
+ * The script is stopped if one of the checks fail.
+ */
+function startSecureSession() {
+	// start session
+	if (isset($_SESSION)) unset($_SESSION);
+	$sessionDir = substr(__FILE__, 0, strlen(__FILE__) - 17) . "/sess";
+	session_save_path($sessionDir);
+	@session_start();
+	// check session id
+	if (! isset($_SESSION["sec_session_id"]) || ($_SESSION["sec_session_id"] != session_id())) {
+		// session id is invalid
+		die();		
+	}
+	// check if client IP has not changed
+	if (!isset($_SESSION["sec_client_ip"]) || ($_SESSION["sec_client_ip"] != $_SERVER['REMOTE_ADDR'])) {
+		// IP is invalid
+		die();
+	}
+	// check if client IP is on the list of valid IPs
+	checkClientIP();
+	// check if session time has not expired
+	// TODO
+}
+
+/**
+ * Checks if the client's IP address is on the list of allowed IPs.
+ * The script is stopped if the host is not valid.
+ *
+ */
+function checkClientIP() {
+	
+}
+
+/**
+ * Checks if the user is allowed to access LAM at this time.
+ * The script is stopped if time is exceeded.
+ *
+ * @param unknown_type $dn
+ */
+function checkUserTime($dn) {
+	
+}
+
+/**
+ * Returns a list of DNs of valid LAM users.
+ *
+ * @param string $dn configuration DN
+ * @return  array $dn user list
+ */
+function getValidUserDNs($dn) {
+	return array("uid=test,o=test", "uid=test2,o=test");
+}
+
+?>
\ No newline at end of file