A method for controlling subsidy locking of a handset device includes storing, in a handset device, an asymmetrically digitally signed subsidy unlock data block that has been modified based on a password after signing (505); modifying the stored unlock data block based on a received subsidy unlock password (510); and granting subsidy unlock status if the asymmetric digital signature of the modified, stored unlock data block properly verifies (510). A method (110) for controlling subsidy locking of a handset device includes storing, in the handset device, an asymmetrically digitally signed subsidy unlock data block that comprises a password portion that has been modified after signing (112); replacing the contents of the modified password portion with a received subsidy unlock password to produce an updated subsidy unlock data block (116); and granting subsidy unlock status if the asymmetric digital signature of the updated subsidy unlock data block properly verifies (118).