Security system and method therefor
First Claim
1. A security system for an automotive vehicle, which comprises a transmitter (1) and a receiver (11) that cooperate to produce a control signal for actuating a security device, and wherein the transmitter (1) comprises:
- a number generator (4) for sequentially generating numbers ai, ai+1,a transmitter-end calculation unit (6) for sequentially calculating transmitter variables di, di+1, based on a predetermined operational expression using the respective numbers ai, ai+1, as a constant, anda transmitting unit (8,9) for sequentially transmitting data to the receiver (11), wherein the data comprises a transmitter variable code obtained by encoding the transmitter variable di and a constant code obtained by encoding the next generated number ai+1, andwherein the receiver (11) comprises;
a receiving unit (14,
13) for receiving the data from the transmitter (1),a receiver-end calculation unit (15) for sequentially calculating receiver variables ei, ei+1, based on the predetermined operational expression, using, respectively the sequentially received numbers ai, ai+1, represented by the constant code in the data received from the transmitter (1), anda controller means (15) for comparing the calculated receiver variable ei with the transmitter variable di represented by the transmitter variable code in the received data, and for outputting a control signal, in response to an affirmative comparison, for actuating the security device.
1 Assignment
0 Petitions
Accused Products
Abstract
When an unlock switch 3 of a transmitter 1 is operated, a random number is generated. A transmitter-end CPU 6 conducts a calculation in accordance with a specified operational expression using the presently generated random number, and the calculation result is renewably stored in a transmitter-end storage 7. Then, an unlock data including an identification code, a calculation result code representative of the calculation result stored in the transmitter-end storage 7 before renewal, and a constant code representative of the presently generated random number is transmitted. On the other hand, in a receiver 11, a calculation is conducted in accordance with the same operational expressed as used in the transmitter 1 using the random number represented by the constant code of the presently received data, and the calculation result is renewably stored. If the identification code in the presently received data agrees with the identification code of a vehicle, the calculation result before renewal is compared with the calculation result represented by the calculation result code in the presently received data. If the calculation results agree, a door lock motor 18 is driven to unlock doors of the vehicle. The doors can be unlocked by a simple operation, and a vehicle theft can be prevented by a simple construction.
-
Citations
17 Claims
-
1. A security system for an automotive vehicle, which comprises a transmitter (1) and a receiver (11) that cooperate to produce a control signal for actuating a security device, and wherein the transmitter (1) comprises:
-
a number generator (4) for sequentially generating numbers ai, ai+1, a transmitter-end calculation unit (6) for sequentially calculating transmitter variables di, di+1, based on a predetermined operational expression using the respective numbers ai, ai+1, as a constant, and a transmitting unit (8,9) for sequentially transmitting data to the receiver (11), wherein the data comprises a transmitter variable code obtained by encoding the transmitter variable di and a constant code obtained by encoding the next generated number ai+1, and wherein the receiver (11) comprises; a receiving unit (14,
13) for receiving the data from the transmitter (1),a receiver-end calculation unit (15) for sequentially calculating receiver variables ei, ei+1, based on the predetermined operational expression, using, respectively the sequentially received numbers ai, ai+1, represented by the constant code in the data received from the transmitter (1), and a controller means (15) for comparing the calculated receiver variable ei with the transmitter variable di represented by the transmitter variable code in the received data, and for outputting a control signal, in response to an affirmative comparison, for actuating the security device. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
-
10. A method for secure access to an automotive vehicle, using a control signal for actuating a security device, comprising the steps of:
-
sequentially generating numbers ai, ai+1, ai+2, . . . ai+n, at a location remote from the vehicle; sequentially calculating transmitter variables di, di+1, di+2, . . . di+n, at the remote location based on a predetermined operational expression using the respective number ai, ai+1, ai+2, . . . ai+n, as a constant in each respective calculation; coding one said transmitter variable di and the next generated number ai+1 as data at the remote location; transmitting the data from the remote location; receiving the data at the vehicle; calculating, at the vehicle, a receiver variable ei using the predetermined operational expression with the number ai received in a previous transmission of data from the remote location; comparing the receiver variable ei calculated at the vehicle with the transmitter variable di transmitted from the remote location; and outputting a control signal in the vehicle based on the step of comparing the receiver variable ei with the transmitter variable di producing an affirmative result, and using said control signal to actuate said security device. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17)
-
Specification