Patent ID: 7227448

Claim:
A system for controlling locking/unlocking means of at least one openable panel of a vehicle, comprising: vehicle transmission/reception means ( 3 , 4 , 5 ) carried by the vehicle, comprising vehicle memory means ( 7 ) comprising a vehicle circular shift register in which is stored a pseudo-random code; vehicle transmission means ( 3 , 6 , 7 ) for transmitting an interrogation signal which carries the pseudo-random code; and vehicle de-spreading means ( 6 , 7 , 8 ) for de-spreading a response signal received unless a pseudo-random code carried by the response signal is not synchronized in substantial correlation with a corresponding pseudo-random code stored in the vehicle memory means ( 7 ) by a time shift less than required for an intermediate transmission means to intercept and retransmit a response signal, and for verifying whether the received signal carries a signature of a user transmission means; and user transmission/reception means ( 9 , 10 , 11 ) intended to be carried by a user for transmitting the response signal for controlling unlocking actuation of the operable panel, comprising user memory means comprising a user circular shift register ( 13 ) in which is stored the pseudo-random code; user de-spreading means ( 12 , 13 , 14 ) for de-spreading the transmission signal received unless the pseudo-random code carried by the interrogation signal is not synchronized in substantial correlation with a corresponding pseudo-random code stored in the user memory means ( 13 ) by a time shift less than required for an intermediate transmission means to intercept and retransmit the interrogation signal; and the user transmission means ( 9 , 12 , 13 , 14 ) for transmitting the response signal which carries the pseudo-random code and the signature which is specific to the user transmission/reception means.