MOBILE INFORMATION TERMINAL, GRIP CHARACTERISTIC LEARNING METHOD, AND GRIP CHARACTERISTIC AUTHENTICATION METHOD

摘要

A mobile information terminal is provided that can obstruct operations by a third party without obstructing operations by an authorized user when shaking or tilting occurs. The mobile information terminal includes: a gripping-feature sample acquisition part that acquires gripping-feature samples; an acceleration sensor that measures an acceleration; a switch that switches the mobile information terminal between a learning state and an authentication state; a template learning part that learns a user authentication template; a tilt counter that adds a tilt score when an acceleration exceeds a predetermined value, and resets the tilt score to 0 when a result of user authentication indicates an authorized user; a user authentication part that performs user authentication; a score adder/subtractor that adds/subtracts a score when a result of user authentication performed by the user authentication part indicates an unauthorized user; a threshold slider that calculates a revised threshold; a locking determination part that determines that the user authentication fails when the score changes across the revised threshold; and a locking part that locks some or all functions of the mobile information terminal when the user authentication fails.