CIPHERING PROCESSOR

摘要

PROBLEM TO BE SOLVED: To realize a high-security ciphering processor which prevent information on a cipher key stored in communication equipment from leaking when the communication equipment is stolen and does not require the addition of a device such as a mischief detection/countermeasure device with a zero-reset circuit. SOLUTION: The cipher key used for a communication with other devices is stored in a volatile storage part 2 and a key for downloading the cipher key stored in the volatile storage part 2 from a key center and the identification number of a fixed station are stored in a nonvolatile storage part 3. The cipher key stored in the volatile storage part 3 is erased by a break of power supply due to a steal to prevent the information on the cipher key from leaking, and the device such as the mischief detection/countermeasure device with the zero- reset circuit becomes unnecessary.