PROTECTION AGAINST RELAY ATTACKS IN A WHITE-BOX IMPLEMENTATION

摘要

A method is provided for performing a cryptographic operation in a white-box implementation on a mobile device. The cryptographic operation is performed in the mobile device for a response to a challenge from a mobile device reader. The mobile device reader includes a time-out period within which the cryptographic operation must be completed by the mobile device. In accordance with an embodiment, a first-time period to complete the cryptographic operation on the mobile device is determined. A predetermined number of dummy computations are added to the cryptographic operation to increase the first-time period to a second-time period. The second-time period is only slightly less than the time-out period by a predetermined safety value to make it less likely a relay attack with be successful.