1. A method for releasing a lock state of a mobile device, comprising: detecting a touch input; distinctively identifying a type of input means corresponding to the touch input and input features of the touch input, wherein the input features comprise a shape of the touch input, an average speed of the touch input and a speed deviation of the touch input; calculating similarities of each of the input features by comparing each of the input features with each of input features of previously stored signature information; setting weights in respect of the similarities of each of the input features, based on the type of input means corresponding to the touch input; calculating a total similarity, based on the similarities of each of the input features and the weights; and determining of releasing the lock state of the mobile device, based on the total similarity.