WIRELESS COMMUNICATIONS SYSTEM

• US 20140355761A1
• Filed: 01/18/2013
• Published: 12/04/2014
• Est. Priority Date: 01/31/2012
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Tokai RIKA Denki Seisakusho
• Original Assignee: Kabushiki Kaisha Tokai RIKA Denki Seisakusho
• Inventors: Kawamura, Daisuke, Kawai, Hideki, Egawa, Tetsuya, Iwashita, Hiroaki, Nagae, Toshihiro
• Granted Patent: US 9,392,448 B2
• Time in Patent Office: Days
• US Class Current: 380/270
• CPC Class Codes: B60R 25/24 using electronic identifiers containing a code not memorised by the user
• CPC Class Codes: G07C 2009/00412 the transmitted data signal being encrypted
• CPC Class Codes: G07C 2009/00793 by Hertzian waves
• CPC Class Codes: G07C 9/00309 operated with bidirectional data transmission between data carrier and locks
• CPC Class Codes: H04L 2209/80 Wireless network architectures or network communication protocols for wireless network security H04W12/00
• CPC Class Codes: H04L 2209/84 Vehicles
• CPC Class Codes: H04L 9/0861 Generation of secret information including derivation or calculation of cryptographic keys or passwords
• CPC Class Codes: H04L 9/3271 using challenge-response
• CPC Class Codes: H04W 12/041 Key generation or derivation
• CPC Class Codes: H04W 12/068 using credential vaults, e.g. password manager applications or one time password [OTP] applications

Abstract

A wireless communications system that regularly executes verification between an electronic key and an immobilizer ECU, and sends and receives deletion request signals unrelated to verification, between the electronic key and the immobilizer ECU. The sending and receiving of deletion request signals is executed at intervals between the regularly executed verifications.

Claims

1. A radio communication system that periodically performs verification between a portable device and a communication subject and exchanges an information signal, which includes information differing from that of the verification, between the portable device and the communication subject,

wherein the exchange of the information signal is performed during a period between a verification and a further verification that are periodically performed.

2. The radio communication system according to claim 1, wherein

the portable device and the communication subject hold the same encryption key, and the verification performed between the portable device and a controller of the communication subject use the encryption key,

the controller stores identification information, which is unique to the communication subject, and a key generation logic, which is used to generate the encryption key,

the portable device stores an encryption key generation code, which is unique to the portable device, and the encryption key, which is generated using the encryption key generation code and the key generation logic,

the controller performs a registration process including

writing the identification information to the portable device through radio communication with the portable device,

retrieving the encryption key generation code from the portable device through radio communication with the portable device,

generating an encryption key that is the same as that of the portable device from the retrieved key generation code using the key generation logic stored in the controller, and

storing the generated encryption key in the controller,

the controller transmits, to the portable device, a deletion request signal, which requests for deletion of the encryption key generation code and serves as the information signal during a period between a present verification and a following verification, and

the portable device deletes the encryption key generation code from the portable device when receiving the deletion request signal.

3. The radio communication system according to claim 1, further comprising:

a database that saves identification information, which is stored in the controller of the communication subject prior to shipment, in association with an additional registration encryption key or an additional registration encryption key generation code; and

a supplemental portable device and a supplemental controller that store the identification information, which is saved in the database, and an encryption key, which is generated from the additional registration encryption key or the additional registration encryption key generation code saved in the database.

4. The radio communication system according to claim 1, wherein the controller of the communication subject deletes the key generation logic from the controller after the encryption key is generated.

5. The radio communication system according to claim 1, wherein

the communication subject repeatedly transmits a signal for performing the verification in intervals of a controlled period, and

the communication subject transmits the information signal whenever the communication subject transmits the signal for performing the verification during the controlled period.

6. The radio communication system according to claim 1, wherein the communication subject transmits the information signal during the controlled period and the verification signal during a period other than the controlled period.

7. The radio communication system according to claim 5, wherein

the portable device stores an encryption key generation code to generate an encryption key used for the verification, and

the communication subject transmits a deletion request signal, which requests for deletion of the encryption key generation code from the portable device and serves as the information signal.