You see, each person's body provides a different amount of opposition to electrical current, so bioimpedance can be a unique biometric identifier.

ENGADGET: Researchers use bioimpedance as a biometric, let health monitor devices know who you are

So, we're a ways off from bioimpedance-based security, but research is ongoing, and you can learn all about it at the source below.

ENGADGET: Researchers use bioimpedance as a biometric, let health monitor devices know who you are

Researchers from Dartmouth have come up with a new way to provide health monitors just such an ability using a tiny electric current and a bioimpedance sensor.

ENGADGET: Researchers use bioimpedance as a biometric, let health monitor devices know who you are

The researchers' idea is to create a bracelet that uses bioimpedance readings to recognize its wearer in a secure, unobtrusive manner and communicate that identity to other wearable devices.

ENGADGET: Researchers use bioimpedance as a biometric, let health monitor devices know who you are