Communication device and system for mobile encrypted communication

• US 5,926,546 A
• Filed: 10/18/1996
• Issued: 07/20/1999
• Est. Priority Date: 10/19/1995
• Status: Expired due to Term

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Yoshida, Ichiro, Ando, Toshihide, Maeda, Asako
• Primary Examiner(s): CANGIALOSI, SALVATORE A
• Application Number:
  US08/733,912
• Time in Patent Office: 1,005 Days
• Field of Search: 380/6, 380/9, 380/23, 380/24, 380/25, 380/49, 340/825.34, 340/928
• US Class Current: 705/65
• CPC Class Codes: B60R 16/0315 using multiplexing techniques multiplexing for transmission of signals G08C15/00; multiplexing for electrical communication in general H04J
• CPC Class Codes: G06Q 20/367 involving electronic purses or money safes
• CPC Class Codes: G07B 15/063 using wireless information transmission between the vehicle and a fixed station identification of vehicles G08G
• CPC Class Codes: H04L 63/0428 wherein the data content is protected, e.g. by encrypting or encapsulating the payload

Abstract

An automatic collection system for automatically collecting a toll charge from an IC card is provided with transceivers in gantries installed along a vehicle road. This collection system uses the transceivers to perform communication with a vehicle-mounted device based on the use of encrypted data. The vehicle-mounted device performs the encryption and decryption of the communication data before its entry into the communication area of the gantries and after its passage therethrough. Also, writing of the data into the IC card, etc. are also performed using encrypted data. However, an algorithm which differs from that used in encrypting the data stored in the IC card and which enables the execution of the high speed processing is used for encrypting the communication data. As a result, since the encryption and decryption of the data is performed only in the roadside device side during communication and this encryption and decryption can be performed at a high speed, the communication time can be shortened to perform accurate data communications within a limited period of time while the vehicle is travelling.

Claims

1. A communication device for installation in a vehicle to perform a communication operation with a roadside device when said communication device is within a communication area of said roadside device, said communication device comprising:

drive means for receiving an IC card that stores predetermined card data;

communication means for performing said communication operation with said roadside device by transmitting transmission data generated based on said card data to said roadside device and by receiving reception data from said roadside device when said communication device is within said communication area of said roadside device; and

cryptographic means for encrypting, using a first encryption algorithm, said card data read through said drive means to generate said transmission data and for decrypting, using said first encryption algorithm, said reception data to obtain decrypted data,

said cryptographic means further encrypting, using a second encryption algorithm different from said first encryption algorithm, a result of said communication operation, and storing said result of said communication operation encrypted using said second encryption algorithm in said IC card through said drive means.

2. A communication device according to claim 1 wherein said communication device is mounted on a vehicle.

3. A communication device according to claim 2, wherein said cryptographic means encrypts said card data before said vehicle enters said communication area of said roadside device.

4. A communication device according to claim 1, wherein said cryptographic means decrypts said reception data after said communication means completes said communication operations with said roadside device.

5. A communication device according to claim 2, wherein said first encryption algorithm has a higher processing speed than said second encryption algorithm.

6. The communication device according to claim 1, further comprising:

verification means for causing said cryptographic means and said IC card to perform a mutual verification operation by exchanging predetermined verification data therebetween when said IC card is inserted inside said drive means and before said cryptographic means generates said transmission data,

wherein said cryptographic means generates said transmission data including a result of said mutual verification operation.

7. A communication device according to claim 6, wherein said predetermined verification data exchanged between said cryptographic means and said IC card is encrypted by said second encryption algorithm.

8. A communication device according to claim 6, further comprising:

error determination means for determining an error in operation of said cryptographic means, said communication means, said drive means, said IC card, and said verification means, and for adding error data indicative of said determined error to said transmission data.

9. The communication device according to claim 1, further comprising:

error determination means for determining an error in operation of said cryptographic means and in said communication means, and for adding error data indicative of determined errors to said transmission data.

10. A vehicle monitoring system for monitoring a vehicle that cruises along a road, said system comprising:

a vehicle-mounted device mounted on said vehicle; and

a roadside device for emitting signals towards a predetermined communication area, said roadside device being installed along said road and performing a communication operation with said vehicle-mounted device when said vehicle is within said communication area,

wherein said vehicle-mounted device comprises;

drive means for receiving an IC card that stores predetermined card data;

communication means for performing said communication operation with said roadside device by transmitting transmission data generated based on said card data to said roadside device and by receiving reception data from said roadside device; and

cryptographic means for encrypting, using a first encryption algorithm, said card data read through said drive means to generate said transmission data and for decrypting, using said first encryption algorithm, said reception data to obtain decrypted data,

said cryptographic means being further for encrypting, using a second encryption algorithm different from said first encryption algorithm, a result of said communication operation of said communication means and storing said result of said communication operation encrypted using said second encryption algorithm in said IC card through said drive means.

11. A vehicle monitoring system according to claim 10, wherein said vehicle-mounted device and said roadside device perform communication operations using communication data that includes an encrypted part and an unencrypted part.

12. A vehicle monitoring system according to claim 11, wherein said communication operations are performed to carry out a toll charge process when the vehicle travels along a toll road, said communication data comprising identity data intrinsic to said vehicle-mounted device and said IC card, process data used for said toll charge process and incidental data other than said identity data and said process data, both said identity data and said process data being encrypted and forming said encrypted part, said incidental data being unencrypted and forming said unencrypted part.

13. A vehicle monitoring system for monitoring a vehicle that cruises along a road, said system comprising:

a vehicle-mounted device mounted on said vehicle; and

a roadside device for emitting signals towards a predetermined communication area, said roadside device being installed along said road and periodically emitting a pilot signal towards said communication area, said roadside device terminating the emission of said pilot signal after said vehicle enters said communication area, performing a communication operation with said vehicle-mounted device by sending and receiving communication data to and from said vehicle-mounted device while said vehicle is within said communication area, transmitting a transmission completion signal to said vehicle-mounted device to indicate completion of said communication operation, and restarting the emission of the periodic emission of said pilot signal after completing said communication operation with said vehicle-mounted device,

wherein said vehicle-mounted device provides a pilot response signal to said roadside device after receiving said pilot signal from said roadside device and subsequently starts said communication operation with said roadside device, said vehicle-mounted device receiving said transmission completion signal from said roadside device after completing said communication operation with said roadside device,

said roadside device terminating said emission of said pilot signal after receiving said pilot response signal from said vehicle-mounted device and starting a periodic emission of said pilot signal immediately after sending said transmission completion signal.

14. A vehicle monitoring system according to claim 13, wherein:

said roadside device sends an unmodulated carrier wave for a predetermined time period to said vehicle-mounted device after sending one of said pilot signal and said communication data to said vehicle-mounted device;

said vehicle-mounted device generating said communication data by modulating said carrier wave signal based on predetermined transmission information and providing said communication data to said roadside device; and

said vehicle-mounted device sending a completion request signal to said roadside device after completing said communication operation with said roadside device unless said roadside device sends said transmission completion.

15. A vehicle monitoring system according to claim 13, wherein:

said roadside device is installed in one of an entrance and an exit of said road, said roadside device decrypting said communication data indicative of toll payment information from said vehicle-mounted device during said communication operation with said vehicle-mounted device, said roadside device performing a toll charge operation to collect a toll charge from said vehicle-mounted device based on said toll payment information, and encrypting a result of said toll charge operation and sending said encrypted result to said vehicle-mounted device;

said vehicle-mounted device sends said encrypted data indicative of said toll payment information during said communication operation with said roadside device;

said vehicle-mounted device receives said encrypted result of said toll charge operation from said roadside device, and decrypts and stores said result; and

said vehicle-mounted device and said roadside device transmit said communication data using a common format.

16. A device for installation in a vehicle for communicating with a roadside device installed in the vicinity of a road traveled by the vehicle, said communication device comprising:

an IC card reader for reading predetermined card data from an IC card, said IC card comprising storage media for storing said predetermined card data;

an encryptor for encrypting, using a first encryption algorithm, said predetermined card data;

a wireless transmitter transmitting to said roadside device transmission data generated based on said predetermined card data and comprising the encrypted predetermined card data;

a wireless receiver receiving from said roadside device reception data when said vehicle is within a predetermined communication range of said roadside device; and

a decryptor for decrypting, using said first encryption algorithm, said reception data;

an encryptor for encrypting, using a second encryption algorithm, data resulting from said communication between said communication device and said roadside device, said second encryption algorithm being different from said first encryption algorithm; and

a write mechanism for storing the encrypted data resulting from said communication in said IC card.

17. A communication device according to claim 16, wherein said first encryptor encrypts said predetermined card data faster than said second encryptor encrypts said data resulting from said communication.

18. A communication device according to claim 16, wherein said communication device is mounted on a vehicle.