US Patent 8430310 Wireless directional identification and verification using wearable electronic devices

Disclosed are systems, methods, and devices for identifying a user associated with a wearable electronic device. First, a directed electromagnetic radiation comprising an identifier associated with a user of the wearable electronic device is transmitted to a first target device. In response, a challenge signal is received requesting a verification response verifying the authenticity of the identifier. The wearable electronic device than detects a predefined user input, and responsive to receiving the challenge signal and detecting the predefined user input, transmits a challenge response corresponding to the predefined user input to a second target device. The first and second target devices may be the same device. The predefined user input may be comprise one or more sensed head movements and/or detected user input operations.