| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a keyless entry system capable of detecting a relay attack by a simple constitution. <P>SOLUTION: A vehicle-side device 2 is equipped with a vehicle-side control portion 12 which performs predetermined control when authenticating an answer signal from a portable machine 3. The portable machine 3 is equipped with a portable-machine control portion 22 which detects intensity of a request signal transmitted from a transmission antenna 15 of the vehicle-side device 2. The vehicle-side control portion 12 controls a vehicle-side transmission portion 11 so that the intensity of the request signal transmitted from the transmission antenna 15 can be changed during the transmission. Furthermore, the portable-machine control portion 22 detects whether the intensity corresponding to the change of the request signal of the received signals is changed or not. <P>COPYRIGHT: (C)2010,JPO&INPIT |
