diff --git a/apps/dav/lib/carddav/sharing/plugin.php b/apps/dav/lib/carddav/sharing/plugin.php
index eeb5abc6d23957da5b9f1c987f9d031b06cbce5c..99c6f8f912c24fad038e040dcdc9118080def091 100644
--- a/apps/dav/lib/carddav/sharing/plugin.php
+++ b/apps/dav/lib/carddav/sharing/plugin.php
@@ -32,7 +32,7 @@ class Plugin extends ServerPlugin {
 	 * This is for example 'versioning' and is added to the DAV: header
 	 * in an OPTIONS response.
 	 *
-	 * @return array
+	 * @return string[]
 	 */
 	function getFeatures() {
 
@@ -77,7 +77,7 @@ class Plugin extends ServerPlugin {
 	 *
 	 * @param RequestInterface $request
 	 * @param ResponseInterface $response
-	 * @return null|bool
+	 * @return null|false
 	 */
 	function httpPost(RequestInterface $request, ResponseInterface $response) {
 
diff --git a/apps/encryption/hooks/userhooks.php b/apps/encryption/hooks/userhooks.php
index 5bd5e39f3c580ec10a8e01a7870ee5f69eaf60a1..4a5f1198fcfc0263e7667934aa03f226c6c3e01c 100644
--- a/apps/encryption/hooks/userhooks.php
+++ b/apps/encryption/hooks/userhooks.php
@@ -141,7 +141,7 @@ class UserHooks implements IHook {
 	 *
 	 * @note This method should never be called for users using client side encryption
 	 * @param array $params
-	 * @return bool
+	 * @return boolean|null
 	 */
 	public function login($params) {
 
@@ -199,7 +199,7 @@ class UserHooks implements IHook {
 	 * If the password can't be changed within ownCloud, than update the key password in advance.
 	 *
 	 * @param array $params : uid, password
-	 * @return bool
+	 * @return boolean|null
 	 */
 	public function preSetPassphrase($params) {
 		if (App::isEnabled('encryption')) {
@@ -216,7 +216,7 @@ class UserHooks implements IHook {
 	 * Change a user's encryption passphrase
 	 *
 	 * @param array $params keys: uid, password
-	 * @return bool
+	 * @return boolean|null
 	 */
 	public function setPassphrase($params) {
 
diff --git a/apps/encryption/lib/crypto/crypt.php b/apps/encryption/lib/crypto/crypt.php
index c0dcc936bdfb0197022cbd001a62c185aeedcd1d..dbc0364a157b5e167e21427830f73a77da426feb 100644
--- a/apps/encryption/lib/crypto/crypt.php
+++ b/apps/encryption/lib/crypto/crypt.php
@@ -34,7 +34,6 @@ use OCA\Encryption\Vendor\PBKDF2Fallback;
 use OCP\Encryption\Exceptions\GenericEncryptionException;
 use OCP\IConfig;
 use OCP\ILogger;
-use OCP\IUser;
 use OCP\IUserSession;
 
 class Crypt {
@@ -146,7 +145,7 @@ class Crypt {
 	/**
 	 * @param string $plainContent
 	 * @param string $passPhrase
-	 * @return bool|string
+	 * @return false|string
 	 * @throws GenericEncryptionException
 	 */
 	public function symmetricEncryptFileContent($plainContent, $passPhrase) {
@@ -273,7 +272,7 @@ class Crypt {
 	}
 
 	/**
-	 * @param $data
+	 * @param string $data
 	 * @return string
 	 */
 	private function addPadding($data) {
@@ -326,7 +325,7 @@ class Crypt {
 	 * @param string $privateKey
 	 * @param string $password
 	 * @param string $uid for regular users, empty for system keys
-	 * @return bool|string
+	 * @return false|string
 	 */
 	public function encryptPrivateKey($privateKey, $password, $uid = '') {
 		$cipher = $this->getCipher();
@@ -343,7 +342,7 @@ class Crypt {
 	 * @param string $privateKey
 	 * @param string $password
 	 * @param string $uid for regular users, empty for system keys
-	 * @return bool|string
+	 * @return false|string
 	 */
 	public function decryptPrivateKey($privateKey, $password = '', $uid = '') {
 
@@ -386,7 +385,7 @@ class Crypt {
 	/**
 	 * check if it is a valid private key
 	 *
-	 * @param $plainKey
+	 * @param string $plainKey
 	 * @return bool
 	 */
 	protected function isValidPrivateKey($plainKey) {
@@ -402,7 +401,7 @@ class Crypt {
 	}
 
 	/**
-	 * @param $keyFileContents
+	 * @param string $keyFileContents
 	 * @param string $passPhrase
 	 * @param string $cipher
 	 * @return string
@@ -424,7 +423,7 @@ class Crypt {
 	 * remove padding
 	 *
 	 * @param $padded
-	 * @return bool|string
+	 * @return string|false
 	 */
 	private function removePadding($padded) {
 		if (substr($padded, -2) === 'xx') {
@@ -436,8 +435,8 @@ class Crypt {
 	/**
 	 * split iv from encrypted content
 	 *
-	 * @param $catFile
-	 * @return array
+	 * @param string|false $catFile
+	 * @return string
 	 */
 	private function splitIv($catFile) {
 		// Fetch encryption metadata from end of file
@@ -457,8 +456,8 @@ class Crypt {
 	}
 
 	/**
-	 * @param $encryptedContent
-	 * @param $iv
+	 * @param string $encryptedContent
+	 * @param string $iv
 	 * @param string $passPhrase
 	 * @param string $cipher
 	 * @return string
@@ -479,7 +478,7 @@ class Crypt {
 	}
 
 	/**
-	 * @param $data
+	 * @param string $data
 	 * @return array
 	 */
 	protected function parseHeader($data) {
@@ -551,7 +550,7 @@ class Crypt {
 	 * @param $encKeyFile
 	 * @param $shareKey
 	 * @param $privateKey
-	 * @return mixed
+	 * @return string
 	 * @throws MultiKeyDecryptException
 	 */
 	public function multiKeyDecrypt($encKeyFile, $shareKey, $privateKey) {
diff --git a/apps/encryption/lib/crypto/encryption.php b/apps/encryption/lib/crypto/encryption.php
index d1140ce7cdeb84b25dd605e95c5072754478ff29..ea6c05c338f63d69725e6ea56208a4b1cfb069d6 100644
--- a/apps/encryption/lib/crypto/encryption.php
+++ b/apps/encryption/lib/crypto/encryption.php
@@ -247,7 +247,7 @@ class Encryption implements IEncryptionModule {
 	 * encrypt data
 	 *
 	 * @param string $data you want to encrypt
-	 * @return mixed encrypted data
+	 * @return string encrypted data
 	 */
 	public function encrypt($data) {
 
@@ -312,7 +312,7 @@ class Encryption implements IEncryptionModule {
 	 * decrypt data
 	 *
 	 * @param string $data you want to decrypt
-	 * @return mixed decrypted data
+	 * @return string decrypted data
 	 * @throws DecryptionFailedException
 	 */
 	public function decrypt($data) {
diff --git a/apps/encryption/lib/keymanager.php b/apps/encryption/lib/keymanager.php
index c45072288780d0735aaf35c40a17526f1f64064a..0c8418c67a87d39518846d53259b9e5d7d997e9f 100644
--- a/apps/encryption/lib/keymanager.php
+++ b/apps/encryption/lib/keymanager.php
@@ -280,7 +280,7 @@ class KeyManager {
 
 	/**
 	 * @param $userId
-	 * @param $key
+	 * @param string $key
 	 * @return bool
 	 */
 	public function setPrivateKey($userId, $key) {
@@ -365,7 +365,7 @@ class KeyManager {
 
 	/**
 	 * @param $userId
-	 * @return mixed
+	 * @return string
 	 * @throws PrivateKeyMissingException
 	 */
 	public function getPrivateKey($userId) {
@@ -379,7 +379,7 @@ class KeyManager {
 	}
 
 	/**
-	 * @param $path
+	 * @param string $path
 	 * @param $uid
 	 * @return string
 	 */
@@ -412,7 +412,7 @@ class KeyManager {
 	/**
 	 * get the encrypted file key
 	 *
-	 * @param $path
+	 * @param string $path
 	 * @return string
 	 */
 	public function getEncryptedFileKey($path) {
@@ -508,7 +508,7 @@ class KeyManager {
 	}
 
 	/**
-	 * @param $purpose
+	 * @param string $purpose
 	 * @param bool $timestamp
 	 * @param bool $includeUserKeys
 	 */
@@ -534,13 +534,16 @@ class KeyManager {
 	}
 
 	/**
-	 * @param $uid
+	 * @param string $uid
 	 * @return bool
 	 */
 	private function deletePrivateKey($uid) {
 		return $this->keyStorage->deleteUserKey($uid, $this->privateKeyId, Encryption::ID);
 	}
 
+	/**
+	 * @param string $path
+	 */
 	public function deleteAllFileKeys($path) {
 		return $this->keyStorage->deleteAllFileKeys($path);
 	}
diff --git a/apps/encryption/lib/migration.php b/apps/encryption/lib/migration.php
index 0b691624a00388775ffe838f92d280362640875d..7bc399ddcbeaa13ce7300db3d4648814b6b1ef39 100644
--- a/apps/encryption/lib/migration.php
+++ b/apps/encryption/lib/migration.php
@@ -237,7 +237,7 @@ class Migration {
 	/**
 	 * rename system wide public key
 	 *
-	 * @param $privateKey private key for which we want to rename the corresponding public key
+	 * @param string $privateKey private key for which we want to rename the corresponding public key
 	 */
 	private function renameSystemPublicKey($privateKey) {
 		$publicKey = substr($privateKey,0 , strrpos($privateKey, '.privateKey')) . '.publicKey';
diff --git a/apps/encryption/lib/recovery.php b/apps/encryption/lib/recovery.php
index e7b20e2c4afb3c835835e78674dfbc88322df84c..cffa641f5175b165bbdfe4abdf0ff2229177778a 100644
--- a/apps/encryption/lib/recovery.php
+++ b/apps/encryption/lib/recovery.php
@@ -103,7 +103,7 @@ class Recovery {
 
 	/**
 	 * @param $recoveryKeyId
-	 * @param $password
+	 * @param string $password
 	 * @return bool
 	 */
 	public function enableAdminRecovery($password) {
@@ -144,7 +144,7 @@ class Recovery {
 	}
 
 	/**
-	 * @param $recoveryPassword
+	 * @param string $recoveryPassword
 	 * @return bool
 	 */
 	public function disableAdminRecovery($recoveryPassword) {
@@ -212,6 +212,7 @@ class Recovery {
 
 	/**
 	 * add recovery key to all encrypted files
+	 * @param string $path
 	 */
 	private function addRecoveryKeys($path) {
 		$dirContent = $this->view->getDirectoryContent($path);
@@ -239,6 +240,7 @@ class Recovery {
 
 	/**
 	 * remove recovery key to all encrypted files
+	 * @param string $path
 	 */
 	private function removeRecoveryKeys($path) {
 		$dirContent = $this->view->getDirectoryContent($path);
diff --git a/apps/encryption/tests/lib/MigrationTest.php b/apps/encryption/tests/lib/MigrationTest.php
index 65fefa262a767d4e1b041b30803cdc60fe882dc9..fc3d014345b726059b3bfa05def14e7ada7947f4 100644
--- a/apps/encryption/tests/lib/MigrationTest.php
+++ b/apps/encryption/tests/lib/MigrationTest.php
@@ -62,6 +62,9 @@ class MigrationTest extends \Test\TestCase {
 		$this->moduleId = \OCA\Encryption\Crypto\Encryption::ID;
 	}
 
+	/**
+	 * @param string $uid
+	 */
 	protected function createDummyShareKeys($uid) {
 		$this->loginAsUser($uid);
 
@@ -89,6 +92,9 @@ class MigrationTest extends \Test\TestCase {
 		}
 	}
 
+	/**
+	 * @param string $uid
+	 */
 	protected function createDummyUserKeys($uid) {
 		$this->loginAsUser($uid);
 
@@ -98,6 +104,9 @@ class MigrationTest extends \Test\TestCase {
 		$this->view->file_put_contents('/files_encryption/public_keys/' . $uid . '.publicKey', 'publicKey');
 	}
 
+	/**
+	 * @param string $uid
+	 */
 	protected function createDummyFileKeys($uid) {
 		$this->loginAsUser($uid);
 
@@ -111,6 +120,9 @@ class MigrationTest extends \Test\TestCase {
 		$this->view->file_put_contents($uid . '/files_encryption/keys/folder2/file.2.1/fileKey'  , 'data');
 	}
 
+	/**
+	 * @param string $uid
+	 */
 	protected function createDummyFiles($uid) {
 		$this->loginAsUser($uid);
 
@@ -124,6 +136,9 @@ class MigrationTest extends \Test\TestCase {
 		$this->view->file_put_contents($uid . '/files/folder2/file.2.1/fileKey'  , 'data');
 	}
 
+	/**
+	 * @param string $uid
+	 */
 	protected function createDummyFilesInTrash($uid) {
 		$this->loginAsUser($uid);
 
@@ -239,6 +254,9 @@ class MigrationTest extends \Test\TestCase {
 
 	}
 
+	/**
+	 * @param string $uid
+	 */
 	protected function verifyFilesInTrash($uid) {
 		$this->loginAsUser($uid);
 
@@ -266,6 +284,9 @@ class MigrationTest extends \Test\TestCase {
 		);
 	}
 
+	/**
+	 * @param string $uid
+	 */
 	protected function verifyNewKeyPath($uid) {
 		// private key
 		if ($uid !== '') {
@@ -394,6 +415,11 @@ class MigrationTest extends \Test\TestCase {
 
 	}
 
+	/**
+	 * @param string $table
+	 * @param string $appid
+	 * @param integer $expected
+	 */
 	public function verifyDB($table, $appid, $expected) {
 		/** @var \OCP\IDBConnection $connection */
 		$connection = \OC::$server->getDatabaseConnection();