diff --git a/include/Swiften/Server/UserRegistry.h b/include/Swiften/Server/UserRegistry.h
new file mode 100644
index 0000000000000000000000000000000000000000..cca4953b3d136f028cc6c574da24deb7a88e4924
--- /dev/null
+++ b/include/Swiften/Server/UserRegistry.h
@@ -0,0 +1,26 @@
+/*
+ * Copyright (c) 2010 Remko Tronçon
+ * Licensed under the GNU General Public License v3.
+ * See Documentation/Licenses/GPLv3.txt for more information.
+ */
+
+#pragma once
+
+#include <string>
+#include <Swiften/Base/SafeByteArray.h>
+#include <boost/signal.hpp>
+
+namespace Swift {
+	class JID;
+
+	class UserRegistry {
+		public:
+			virtual ~UserRegistry();
+
+			virtual bool isValidUserPassword(const JID& user, const SafeByteArray& password) const = 0;
+
+			boost::signal<void (const std::string &user)> onPasswordValid;
+			boost::signal<void (const std::string &user)> onPasswordInvalid;
+
+	};
+}