| 摘要 |
An invalid access/security device is provided to the user of a valid access/security device. The authorised user is able to differentiate between valid and invalid devices by their physical characteristics and uses the valid device. The issuer is able to distinguish devices by using identifying characteristics recorded on the device. The use of an invalid device can be detected and assumed to be by an un-authorised user, security measures can therefore be instigated. An un-authorised user cannot determine which device gives access to a valuable resource or that which triggers security measures. There is a deterrent to un-authorised use and an increased chance of detection of unauthorised use. |
