Being detection manner of the breakdown attack altering the contents of memory and the manner which detects the security

摘要

PROBLEM TO BE SOLVED: To provide a security device capable of detecting that an instruction stored in a memory changes to such an instruction specified in advance in the security device (for example, NOP instruction) when an IC chip mounted on the security device is irradiated with laser beam as failure attack to the security device.;SOLUTION: A VM10 mounted on an IC card 1 which is a security device comprises a fetching means 100 which fetches an execution operation code from an EEPROM22, a specified operation code detecting means 101 which detects that the fetching means 100 has fetched the operation code of an instruction specified in advance in the IC card 1 (for example, operation code of NOP instruction), and an execution operation code validation means 102 which validates the validity of execution operation code when the specified operation code is fetched. The VM10 executes a process for stopping an operation of VM10 if validating the validity of the execution operation code fails.;COPYRIGHT: (C)2010,JPO&INPIT