US Patent 9679128 De-authentication of wearable devices

A wearable device comprises a first member, a second member that is configured to move relative to the first member, a sensor disposed on the first member, one or more components disposed on the second member, and an authentication module. The sensor is configured to output a sense signal that is indicative of a distance between the sensor and at least one of the one or more components. When the wearable device is worn by a user, the wearable device may be authenticated. The sense signal indicates when at least a portion of the wearable device is opened and/or removed. The wearable device may be de-authenticated based at least in part on the sense signal indicating that a portion of the wearable device has been opened or removed.