Generate strong, human readable OTP

Signed-off-by: J0WI <J0WI@users.noreply.github.com>

apps/encryption/lib/Crypto/EncryptAll.php

@@ -394,7 +394,7 @@ class EncryptAll {
 	 * @return string password
 	 */
 	protected function generateOneTimePassword($uid) {
-		$password = $this->secureRandom->generate(8);
+		$password = $this->secureRandom->generate(16, ISecureRandom::CHAR_HUMAN_READABLE);
 		$this->userPasswords[$uid] = $password;
 		return $password;
 	}