Patent ID: 8745752

Claim:
A detection method for detecting fraud on an electronic device machine installed in a housing of a user operation terminal for a user to conduct operation; wherein the electronic device machine includes: a first detection device is configured to detect a removal from the housing; a first memory chip that can erase removal detection recognition data, being stored therein, according to an output signal from the first detection device; a second memory chip, being independent of the first memory chip, and storing current authentication key data; and wherein the method comprises: erasing a first removal detection recognition data when the electronic device machine is removed from the housing; changing the current authentication key data to new authentication key data after completing predetermined authentication procedures when the electronic device machine is re-mounted into the housing, the predetermined authentication procedures being executed when a removal of the electronic device from the housing is detected and tampering is not detected, and the predetermined authentication procedures using the current authentication key data to verify whether a device is authentic; and storing the new authentication key data in the second memory chip; wherein, when the current authentication key data are changed to new authentication key data, the electronic device automatically creates new second removal detection recognition data and stores the new removal detection recognition data in the first memory chip.