A method for unlocking a handheld device with a touch screen includes accessing a social network using login information, acquiring information of a plurality of friends from the social network. The method further includes creating an unlocking interface on the touch screen according to a second amount of a secondary key based on the plurality of friends and a question based on the first amount of a primary key based on the plurality of friends. An input event of a user on the unlocking interface is detected the handheld device is transitioned from a lock state to an unlock state upon the condition that the input event corresponds to a correct answer.