| 摘要 |
PROBLEM TO BE SOLVED: To make the unauthorized copy of program data impossible even when execution is performed in a non-protective environment. SOLUTION: A program is ciphered and stored in a ROM 32. A security chip responds to an appropriate request from a processor 20, deciphers the program data and returns them to the processor 20, however, when the request is inappropriate, the treatment of stopping the processor 20 or the like is performed. A branching instruction is processed inside the security chip 30. A value required for deciphering is stored in a volatile memory inside the security chip 30, however, when the security chip 30 is peeled off, the contents of the volatile memory are lost. |
