A Toronto-based, security start-up Bionym has stepped in to solve this issue once for all and make passwords a passe. It has designed and developed Nymi, a "wearable authentication wristband" that authenticates you and identifies the unique signature of your heartbeat to unlock your devices, a significant advantage over other wearables such as the NFC ring.
To access a device, you need to touch the top of the Nymi for a few seconds. The device confirms the wearer's identity through electrocardiogram (ECG) sensors that monitor the heartbeat, and communicates via Bluetooth, the authentication to an app on you iOS and Android devices as well as Windows and OS X computers, making sure the only way your devices will unlock is, if you're the person wearing the accessory. When you remove the Nymi, the devices linked to it gets locked automatically.
If ever someone decided to whack it away, they would have to take you along. You can be sure that your devices will remain safe because it does not store any heartbeat and reactivates every time you put it back on. Its proximity sensors ensure that your devices are unlocked only when it's close to your wrist.
Having tested the device on a 1000 people so far, Nymi was found to be better than facial recognition, or almost similar to fingerprint authentication in terms of accuracy.
While on one hand this certainly seems like a technology with potential, on the other hand it remains unclear how it would work under certain heart conditions such as the presence of a pacemaker or other cardiac ailments. For now, the minimum requirement for this device to work seems to be that the user must be alive and not in a state of cardiac arrest.
The Nymi wristband will hit the market early 2014, but Bionym had started taking preorders starting September 4th 2013. [The Verge]