Title of Invention

"A DEVICE FOR PERFORMING AUTHORIZATION OF AN IGNITION KEY"

Abstract

A system for performing authorization of an ignition key comprising an engine control unit (ECU), an ignition key that stores a key ID, a lock password and a key password; and a transponder provided within the ignition key , wherein the ECU performs the steps S210 to S240 of: 1) receiving the key ID from the ignition key and determining if the Key ID is a registered ID; and 2) generating, if the key ID is the registered ID, a random number and encoding a stored lock password using the random number, and transmitting the random number and the encoded lock password to the transponder of the ignition key , and accordingly the transponder performs the steps S242 to S270 of: 3) decoding the lock password using the received random number and encoded lock password, then determining if the decoded lock password is identical to a stored lock password; and 4) encoding a key password using a stored key password, and transmitting the encoded key password to the ECU, and accordingly the ECU performs the steps S272 to S290 of: 5) decoding the received encoded key password, then determining if the decoded key password is identical to the stored key password; and 6) releasing an ignition lock state if the decoded key password is identical to the stored key password.

Full Text

We Claim: 1. A device for performing authorization of an ignition key 120 comprising: an engine control unit (ECU) 150; an ignition key 120 that stores a key ID, a lock password and a key password; and a transponder 110 provided within the ignition key 120, wherein: the ECU 150 performs the steps S210 to S240 of: 1) receiving the key ID from the ignition key and determining if the ey ID is a registered ID; and 2) generating, if the key ID is the registered ID, a random number and encoding a stored lock password using the random number, and transmitting the random number and the encoded lock password to the transponder 110 of the ignition key 120, and accordingly the transponder 110 performs the steps S242 to S270 of: 3) decoding the lock password using the received random number and encoded lock password, then determining if the decoded lock password is identical to a stored lock password; and 4) encoding a key password using a stored key password, and transmitting the encoded key password to the ECU, and accordingly the ECU performs the steps S272 to S290 of: 5) decoding the received encoded key password, then determining if the decoded key password is identical to the stored key password; and 6) releasing an ignition lock state if the decoded key password is identical to the stored key password. 2. The system as claimed in claim 1 wherein the ECU comprises shift registers T and S, and the encoding of the lock password in step (2) comprises the steps of: 7) initializing and modulating the shift registers T and S using the random number; 8) generating a first cession key; and 9) encoding the stored lock password using the first cession key, and wherein the decoding of the lock password using the random number and encoded lock password in step (3) are performed using the same processes involved in encoding the stored lock password using the random number of step (2). 3. The device as claimed in claim 2 wherein the initialization of the shift registers of step (7) comprises the steps of generating a random number, and wherein the shift register modulation of step (7) is realized by designating a plurality of functions that receives input of a plurality of functions that receive input of a plurality of bit values and calculate a single bit value; designating an F2 function that receives input of calculation result values from the functions and calculates bit values; and repeating processes in which the shift registers T and S are shifted to the left, and determining an LSB of the shift register S using the F2 function values and the random number. The device as claimed in claim 3 wherein in the generation of the first cession key of step (8), a plurality of functions are designated that receives input of a plurality of bit values and calculate a single bit value and F3 function is designated that receives input of calculation result values from the functions and calculates bit values, and bits of the first cession key are calculated from the F3 function values. The system as claimed in claim 4 wherein the plurality of functions is identical to the plurality of functions of step (7), and the F3 function is identical to the F2 function. The device as claimed in claim 1 wherein the ECU comprises shift Registers T and S, wherein encoding of the stored key password of step (4) comprises the steps of: 10) generating a second cession key; and 11) encoding the stored key password using the second cession key; and wherein the decoding of the encoded key password in step (5) is performed using the same processes as are involved in the encoding of the key password. The device claimed in claim 6 wherein in the generation of the second session key of step (10), a plurality of functions are designated that receive input of a plurality of bit values and calculate a single bit value, an F4 function is designated that receives input of calculation result values from the functions and calculates bit values, and bits of the second cession key are calculated from the F4 function values. 8. A device for performing authorization of an ignition key substantially as herein described with reference to and as illustrated by the accompanying drawings.

Documents:

974-del-2001-abstract.pdf

974-del-2001-claims.pdf

974-del-2001-correspondence-others.pdf

974-del-2001-correspondence-po.pdf

974-del-2001-description (complete).pdf

974-del-2001-drawings.pdf

974-del-2001-form-1.pdf

974-del-2001-form-18.pdf

974-del-2001-form-2.pdf

974-del-2001-form-3.pdf

974-del-2001-form-5.pdf

974-del-2001-pa.pdf