Abstract: An access violation of the program is monitored by the access monitor which is a hardware. The access monitor acquires a signal input from the CPU to a memory. The access monitor includes an access permission table as information of the memory region to be permitted to each program, and detects the access violation of the signal from the CPU by referring thereto. In this manner, the unjust access is monitored by the hardware, thereby preventing the unjust access by rewriting in software.

Abstract: An encryption processor for encrypting and decrypting data that ensures data security by preventing illegal deciphering or leakage of the data. The encryption processor includes a CPU for running a program, a ROM for storing the program run by the CPU, a RAM used as a work area while the CPU is running the program, an I/O section for sending/receiving data to/from an external device, and an encryption section for decrypting encrypted data and encrypting plain text data.

Abstract: A protocol control integrated circuit configured by integrating, on one chip, hardware and control programs necessary for conducting data interchange through communications with portable type mediums, and used in common among various types of apparatus. Thus, the integrated circuit is constructed by integrating, on one chip, a storage section for storing a control program prepared for protocols for a plurality of digital money different in mode from each other, a processing section for controlling the handling of the plurality of digital money, different in mode, by running the control program stored in the storage section, and an interface circuit connected to an external circuit including at least one of an external processing section and an external storage section for fulfilling an interface function between the external circuit and the processing section. Further this invention is applicable to various types of transaction apparatus capable of handling, for example, digital money and credit transactions.

Abstract: An encryption control apparatus for encrypting and decrypting data that ensures data security by preventing illegal deciphering or leakage of the data is provided. A CPU 11A for running a program, a ROM 13A for storing the program run by the CPU, a RAM 12A used as a work area while the CPU is running the program, an I/O section 14A for sending/receiving data to/from an external device, and an encryption section 15A for decrypting encrypted data and encrypting plain text data are formed on a single semiconductor device.

Abstract: An access violation of the program is monitored by the access monitor which is a hardware. The access monitor acquires a signal input from the CPU to a memory. The access monitor includes an access permission table as information of the memory region to be permitted to each program, and detects the access violation of the signal from the CPU by referring thereto. In this manner, the unjust access is monitored by the hardware, thereby preventing the unjust access by rewriting in software.

Abstract: Each application is provided with amounts and conditions for selection of applications, which are previously stored in an application selection table (22) of an IC card (100). Thereby, the amounts within predetermined ranges are corresponded to specific applications. The above IC card (100) performs automatic selection of applications corresponding to the amounts by an application selection section (23) based on amount information received from an external device.