A portable device includes a reception antenna and a strength meter. The reception antenna includes antennas of three axes each receiving a first signal and a second signal. The strength meter measures a reception strength of the request signal and the request signal received by each of the three axes of the LF receiver. A relay attack determination device is provided with a comparator that executes a comparative process of strength ratios of the request signal and the request signal based upon a measurement value of the reception strength. In a case where the three axes include an ineffective axis, in which the measurement value of the reception strength of the request signal or the request signal deviates from a usable range, the comparator excludes the ineffective axis and executes the comparative process.
Relay Attack Determination Device
01.12.2022
Patent
Elektronische Ressource
Englisch