A hardware TPM has a plurality of registers, and performs data protection by encryption of data associated with the value of one of the plurality of registers. A register number manager manages, for each application, a register number used for the data protection. During execution of an application, an application executor issues a data protection request that designates a register number preset in the application. A software TPM transfers, to the hardware TPM, the data protection request in which the register number designated in the data protection request has been replaced with the register number managed by the register number manager.