diff --git a/lib/public/encryption/imanager.php b/lib/public/encryption/imanager.php
index 3cb30f8ee89e8557d252c43284e3824649d6c872..0b12c7524d293ba5fba89c409e4863703cb5bd28 100644
--- a/lib/public/encryption/imanager.php
+++ b/lib/public/encryption/imanager.php
@@ -37,7 +37,7 @@ interface IManager {
 	 * @return bool true if enabled, false if not
 	 * @since 8.1.0
 	 */
-	function isEnabled();
+	public function isEnabled();
 
 	/**
 	 * Registers an callback function which must return an encryption module instance
@@ -48,7 +48,7 @@ interface IManager {
 	 * @throws ModuleAlreadyExistsException
 	 * @since 8.1.0
 	 */
-	function registerEncryptionModule($id, $displayName, callable $callback);
+	public function registerEncryptionModule($id, $displayName, callable $callback);
 
 	/**
 	 * Unregisters an encryption module
@@ -56,7 +56,7 @@ interface IManager {
 	 * @param string $moduleId
 	 * @since 8.1.0
 	 */
-	function unregisterEncryptionModule($moduleId);
+	public function unregisterEncryptionModule($moduleId);
 
 	/**
 	 * get a list of all encryption modules
@@ -64,18 +64,18 @@ interface IManager {
 	 * @return array [id => ['id' => $id, 'displayName' => $displayName, 'callback' => callback]]
 	 * @since 8.1.0
 	 */
-	function getEncryptionModules();
+	public function getEncryptionModules();
 
 
 	/**
 	 * get a specific encryption module
 	 *
-	 * @param string $moduleId
+	 * @param string $moduleId Empty to get the default module
 	 * @return IEncryptionModule
 	 * @throws ModuleDoesNotExistsException
 	 * @since 8.1.0
 	 */
-	function getEncryptionModule($moduleId);
+	public function getEncryptionModule($moduleId = '');
 
 	/**
 	 * get default encryption module Id