INFORMATION PROCESSING DEVICE

摘要

A device structure for reliably encrypting and decrypting information is provided, which is used for security with information processing device, a communication device and a file management device. Such devices comprise a plurality of semiconductor parts. Therefore, confidential data may remain in devices, for example, in a system bus and semiconductor memory for main storage. To solve this problem, a device CPU is equipped with a microprocessor, an encryption algorithm ROM, an encryption hardware, RAM, a key storage area, and an external bus control, which are all integrated into a single semiconductor chip. Encryption and decryption take place only within the CPU, and the internal operations of the CPU cannot be inferred from signals outside the CPU.