A memory card includes a nonvolatile memory chip and a controller chip. The controller chip includes a first encrypting portion and a second encrypting portion. The first encrypting portion decrypts data input to the memory card that have been encrypted using a first key that is different for each session, using the first key. The second encrypting portion encrypts the data that are decrypted by the first encrypting portion using a second key. The nonvolatile memory chip stores the data encrypted by the second encrypting portion. <IMAGE>
