Patent ID: 7303135

Claim:
A semiconductor memory card comprising: a nonvolatile memory that stores a file constituted by an entity and management information; and a tamper-resistant module that includes a processing unit and an internal memory, the processing unit including: an analysis unit operable to analyze a command issued by a device to which the semiconductor memory card is connected and generate an event corresponding to a result of the analysis; and a deletion unit operable to, if a deletion event for the file is generated, (i) create a location table on the internal memory in the tamper-resistant module, and (ii) overwrite the management information, wherein the location table indicates a location of the entity, and is referred to by the deletion unit when the deletion unit overwrites the entity, the internal memory stores an encryption key with which the entity has been encrypted, and the deletion unit includes: a main deletion unit operable to, if the deletion event is generated, first overwrite the encryption key with which the entity has been encrypted and subsequently create the location table and overwrite the management information; and a sub deletion unit operable to, if an event different from the deletion event is generated, overwrite the entity with reference to the created location table.