Researchers have developed a wearable device that measures electrocardiogram readings, which are unique to every person, that the researchers hope could be used as an alternative to passwords for authentication. The device is called Nymi, and it wears like a wristwatch but contains two electrodes. When a user touches his or her fingertip to the second electrode, a circuit is established and the user s heart rhythm is monitored, producing an ECG. This ECG is then analyzed by a piece of software developed by Bionym and packaged with the device as an application.
Source: https://threatpost.com/watch-like-heartbeat-monitor-seeks-to-replace-passwords/102192/