Wearable computer apparatus with same hand user authentication

Apparatuses, methods and storage medium associated with same hand user authentication are disclosed herein. In embodiments, an apparatus, wearable on a user's wrist, may include a user authentication module to authenticate and grant access to the user. To authenticate the user, the user authentication module may be configured to receive sensor data indicative of movements of one or more fingers over a virtual grid, analyze the sensor data to determine the movements, and authenticate and grant the user access or deny the user access to the apparatus based at least in part on a result of the analysis. The one or more fingers are fingers of a hand of the user that adjoins the wrist on which the apparatus is worn. In embodiments, the senor data may include sensor data collected by sensors configured to measure tendon/muscle positions of the wrist. Other embodiments may be disclosed or claimed.