A system for authenticating a memory card including: a memory card host device including a plural area authentication module which judges whether the memory card has plural storage areas, and an area switching module which switches a storage area subject to access a different storage area from among plural storage areas; a memory card including plural storage areas, at least one internal register which retains a value indicating the number of storage areas, and a controller which transmits the value indicating the number of the storage areas to the memory card host device; and a bus which transmits and receives data between the memory card host device and the memory card.