VEHICLE SECURITY ARRANGEMENT

摘要

A vehicle security arrangement including a first part for incorporation in a vehicle and a second part for use as a key to allow operation of the vehicle, in which arrangement both the first part and the second part include signal processing means and signal receiving and sending means, the signal processing means being responsive to an input signal of a first value to generate an output signal of a second value in accordance with a one-way hash function performed with a stored value on the first value, the stored value being computationally unfeasible to determine from the first and second values, the first part including means to produce a first value signal and in operation send this first value signal for the second part, in operation in the key position for the vehicle, to receive as a said input signal therefor and form a said second value output signal therefrom, the first part also including means to receive said output signal of the second part sent therefrom together with means to compare the received said output signal with a check value generated from the produced first value by the signal processing means of the first part and permit or prevent operation of the vehicle in accordance with the result of the comparison following the signal exchange.