You can use as complex as a password as you like, but that won't do you much good if someone's able to watch or record you entering it. Researchers Andrea Bianchi, Ian Oakley and Dong-Soo Kwon have some ideas for overcoming that little problem though, and recently put together a video demonstrating a few of the possibilities they've come up with. All of those rely on haptic input systems -- either on their own or in conjunction with some audio output (through headphones for privacy). That includes things like a dedicated haptic keypad or haptic wheel, and different methods that could take advantage of a haptic display on a smartphone. As you can see in the video after the break, some of those options could be a bit more time consuming than an easy-to-remember password, but there's certainly plenty of potential applications where security would trump convenience.