Patent ID: 7584366

Claim:
A method of detecting tampering of electronic equipment comprising: instructing the electronic equipment to perform at least one computational operation at the electronic equipment to produce a result; receiving the result from the electronic equipment; detecting tampering of the electronic equipment if the result is not received within a constrained time of the instructing, even if the result is correct; and disconnecting the electronic equipment from a network by which it communicates and/or at least partially disabling the electronic equipment upon detecting tampering; wherein detecting comprises: determining a first time to instruct the electronic equipment to perform at least one computational operation; determining a second time to perform at least one computational operation at the electronic equipment to produce the result; determining a third time to receive the result from the electronic equipment; and detecting tampering of the equipment if the result is not received within a constrained time that is a function of the first, second and third times, even if the result is correct.