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 first firmware data and first sorting hash data related to the first firmware data, and it divides a first hash data generated from the first firmware data into a plurality of data groups, and re-assembles the data groups according to a mapping and sorting algorithm to generate second sorting hash data. The controller includes an efuse region for writing the mapping and sorting algorithm. When the controller determines that the second sorting hash data is identical to the first sorting hash data, the first firmware data is allowed to update the controller.