| 摘要 |
<P>PROBLEM TO BE SOLVED: To further improve security by making camouflage of a position at which an electronic key exists using a wireless technique, difficult in an electronic key system. <P>SOLUTION: A vehicle-mounted device 20 determines validity of a movement of a user carrying an electronic key 10 based on aspects of variation of signal strengths of request signals Sro, Sri detected by an RSSI detection circuit 16. When it is determined that the movement of the user is not valid, it is determined as unclear whether a proper user is actually near a vehicle 2 or not, and unlock of a vehicle door or start of an engine is not allowed. In this manner, in addition to collation of ID codes, by authenticating whether the movement of the user (electronic key 10) is proper or not, camouflage of a position at which the electronic key 10 exists, is made difficult, to improve security of the electronic key system 1. <P>COPYRIGHT: (C)2011,JPO&INPIT |
