Patent ID: 8117449
Filing Date: 2012-02-14
Classification: H04L

Abstract:
1. A method for detecting a communication relay attack comprising the steps of: establishing a communication link between a wireless payment device and a data receiving device; transmitting a clock signal from said data receiving device to said wireless payment device for synchronizing data communication between said wireless payment device and said data receiving device; transmitting data from said wireless payment device to said data receiving device, said data having a first predefined element and a second predefined element; counting a number of clock cycles occurring in said clock signal between transmission of said first predetermined element of said data and transmission of said second predefined element of said data with said wireless payment device; counting a number of clock cycles occurring in said clock signal between receipt of said first predefined element of said data and receipt of said second predefined element of said data with said data receiving device; comparing said number of clock cycles counted by said wireless payment device with said number of clock cycles counted by said data receiving device; and determining that a communication relay attack has occurred if said number of clock cycles counted by said wireless payment device differs from said number of clock cycles counted by said data receiving device, wherein said first predefined element of said data includes an instruction for said data receiving device to start counting said clock cycles and said second predefined element of said data includes an instruction for said data receiving device to stop counting said clock cycles.