A mobile terminal and a method of operating the mobile terminal are provided. The mobile terminal includes a sensor configured to sense a motion of the mobile terminal, and a communication interface configured to receive, from a wearable device corresponding to the mobile terminal, information of a motion of the wearable device, the motion of the wearable device being sensed during a time period from a start time requested by the mobile terminal. The mobile terminal further includes a controller configured to determine whether the motion of the mobile terminal and the motion of the wearable device have a correlation of a level or greater, and unlock the mobile terminal, in response to the controller determining that the motion of the mobile terminal and the motion of the wearable device have the correlation of the level or greater.