A data storage device utilized for confirming firmware data includes a flash memory and a controller. The controller is coupled to the flash memory to receive at least one first hash data related to a first firmware data, and it divides the first hash data into a plurality of data groups. The controller sorts the data groups based on a predetermined sorting mechanism to generate a first sorting hash data. The controller includes an efuse region for writing the predetermined sorting mechanism. When the controller determines that a second sorting hash data of a second firmware data is identical to the first sorting hash data or a second hash data of the second firmware data is identical to the first hash data, the second firmware data is allowed to update the controller.