Digital certificate pool

• US 7,734,050 B2
• Filed: 03/27/2006
• Issued: 06/08/2010
• Est. Priority Date: 03/27/2006
• Status: Expired due to Fees

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Technical Center North America Incorporated (Nissan Motor Co., Ltd.)
• Inventors: Andrews, Scott, Heft, Ronald, Tengler, Steve
• Primary Examiner(s): Bui; Kieu Oanh
• Assistant Examiner(s): Woldemariam; Nega
• Application Number:
  US11/389,858
• Publication Number:
  US 20070223702A1
• Time in Patent Office: 1,534 Days
• Field of Search: 380/200, 380/30, 713/192, 713/168, 713/182, 726/4, 726/13, 726/30, 726/24, 709/12, 709/14
• US Class Current: 380/270
• CPC Class Codes: H04L 2209/42 Anonymization, e.g. involving pseudonyms
• CPC Class Codes: H04L 2209/80 Wireless
• CPC Class Codes: H04L 2209/84 Vehicles
• CPC Class Codes: H04L 9/3263 involving certificates, e.g. public key certificate [PKC] or attribute certificate [AC]; Public key infrastructure [PKI] arrangements network architectures or network communication protocols for supporting authentication of entities using certificates in a packet data network H04L63/0823

Abstract

A wireless vehicle and infrastructure system is described that allows for utilization of a quasi-anonymous common private key/digital certificate pool, such that all vehicles are authenticated to the system, but no one vehicle/user can be readily identified during their use of the system because of their use of set of common private key/digital certificate pairs that are assigned to each vehicle from the pool and are common across multiple vehicles. Vehicle/user anonymity is only temporarily removed during vehicle/user re-authentication and re-issuance of new common private key/digital certificate pairs from the pool in the wireless vehicle and infrastructure system.

Claims

1. A method of assigning a plurality of private keys to a vehicle in a wireless system, the method comprising:

generating a vehicle identifier that is indicative of the vehicle based on at least one of a hardware configuration and a software configuration of the vehicle such that the vehicle identifier changes when the at least one of the hardware configuration and the software configuration changes;

encrypting the vehicle identifier at the vehicle;

sending a request for the private keys with the encrypted vehicle identifier from the vehicle to a certificate authority;

obtaining an authentication of the vehicle based on the encrypted vehicle identifier to assign the private keys to the vehicle;

selecting the plurality of private keys from a pool of common private keys, at least one of the selected private keys being used for encrypting a message at the vehicle, and each of the private keys in the pool of common private keys being shared by a plurality of vehicles;

sending the selected private keys to the vehicle; and

storing the selected private keys in the vehicle.

2. The method of claim 1, wherein

the wireless system is a Dedicated Short Range Communications (DSRC) wireless system.

3. The method of claim 1, wherein

the vehicle identifier is one of a vehicle ID, a VIN, and a configuration key.

4. The method of claim 3, wherein

the configuration key is generated internally by the vehicle from one or more of a VIN, one or more electronic serial numbers (ESNs) of vehicle systems, an identifier of on board equipment, and one or more vehicle software version numbers.

5. The method of claim 1, wherein

the selecting of the private keys from the pool of the common private keys, the sending of the selected private keys to the vehicle, and the storing of the selected private keys in the vehicle further includes generating a private certificate from a vehicle configuration key such that the private certificate corresponds to one of the private keys from the pool of the common private keys, sending the selected private certificate to the vehicle, and storing the selected private certificate in the vehicle, the vehicle generating each of the selected private keys from the private certificate by utilizing the vehicle identifier.

6. The method of claim 1, wherein

the storing of the selected private keys in the vehicle further includes storing each of the selected private keys as a valid private key in a set of currently valid private keys.

7. The method of claim 1, wherein

the selecting of the private keys from the pool of the common private keys, the sending of the selected private keys to the vehicle, and the storing of the selected private keys in the vehicle further includes selecting a plurality of private key/digital certificate pairs from a pool of common private key/digital certificate pairs, sending the selected private key/digital certificate pairs to the vehicle, and storing the selected private key/digital certificate pairs in the vehicle.

8. The method of claim 1, wherein

the sending of the selected private keys to the vehicle and the storing of the selected private keys in the vehicle further includes encrypting the selected private keys with a certificate authority private key, sending the selected private keys to the vehicle, decrypting the selected private keys at the vehicle with the certificate authority public key, and storing the selected private keys in the vehicle.

9. The method of claim 1, wherein

the encrypting of the vehicle identifier at the vehicle further includes encrypting the vehicle identifier at the vehicle with a system public key, the system public key including a configuration authority public key or an original equipment manufacturer public key, and

the obtaining of the authentication of the vehicle further includes decrypting the encrypted vehicle identifier at the certificate authority with a system private key and authenticating the vehicle against a list of valid vehicle identifiers.

10. A method of operating a wireless system, the method comprising:

sending a message to the wireless system from a vehicle by randomly using a different private key/digital certificate pair from a set of valid private key/digital certificate pairs stored on the vehicle to sign the message being sent to the wireless system, the wireless system maintaining a pool of current valid common private key/digital certificate pairs that includes the set of the valid private key/digital certificate pairs, each of the private key/digital certificate pairs in the pool of currently valid common private key/digital certificate pairs being shared by and stored in a plurality of vehicles;

preparing a certificate revocation list message including a list of revoked private key/digital certificate pairs to be revoked;

revoking a valid private key/digital certificate pair by sending the certificate revocation list message from the wireless system to the vehicle, and the vehicle removing the revoked private key/digital certificate pairs on the certificate revocation list message from the vehicle;

sending a request for a new currently valid private key/digital certificate pair with an encrypted vehicle identifier from the vehicle to a certificate authority with the vehicle identifier being indicative of the vehicle and based on at least one of a hardware configuration and a software configuration of the vehicle such that the encrypted vehicle identifier changes when the at least one of the hardware configuration and the software configuration changes;

obtaining an authentication of the vehicle based on the encrypted vehicle identifier to assign the new currently valid private key/digital certificate pair; and

receiving and storing on the vehicle the new currently valid private key/digital certificate pair from the pool of currently valid common private key/digital certificate pairs that is selected and assigned by the certificate authority.

11. The method of claim 10, wherein

the wireless system is a Dedicated Short Range Communications (DSRC) wireless system.

12. The method of claim 10, further comprising

revoking an access right of the vehicle to the wireless system when the vehicle has replaced the revoked private key/digital certificate pair more than a predetermined threshold,

the sending of the request for the new currently valid private key/digital certificate pair with the vehicle identifier, the obtaining of the authentication of the vehicle, and the receiving and storing of the new private key/digital certificate pair further including:

encrypting the vehicle identifier of the vehicle;

sending the encrypted vehicle identifier from the vehicle to the certificate authority;

decrypting the encrypted vehicle identifier at the certificate authority;

authenticating the vehicle against a list of valid vehicle identifiers;

selecting a private key/digital certificate pair from the pool of valid common private key/digital certificate pairs;

encrypting and sending the selected private key/digital certificate pair to the vehicle; and

decrypting and storing the selected private key/digital certificate pair in the vehicle.

13. The method of claim 10, wherein

the sending of the message to the wireless system from the vehicle and the sending of the certificate revocation list message from the wireless system to the vehicle further includes sending the message to a second vehicle from the vehicle and sending the certificate revocation list message from the second vehicle to the vehicle.

14. The method of claim 10, wherein

the vehicle identifier is one of a vehicle ID, a VIN, and a configuration key.

15. The method of claim 14, wherein

the configuration key is generated internally by the vehicle from one or more of a VIN, one or more electronic serial numbers (ESNs) of vehicle systems, an identifier of on board equipment, and one or more vehicle software version numbers.

16. The method of claim 10, wherein

each private key/digital certificate pair is a private certificate/digital certificate pair, and

the vehicle generates each private key from a private certificate by utilizing the vehicle identifier.

17. The method of claim 16, wherein

each private key is generated from a stored private certificate utilizing the vehicle identifier by sequentially encrypting or signing an outgoing message with the vehicle identifier and the stored private certificate.

18. The method of claim 16, wherein

each private key is pre-generated for use in encrypting or signing outgoing messages upon vehicle start-up from each private certificate stored in the vehicle utilizing the vehicle identifier.

19. A method of operating a vehicle to communicate based on a public-key cryptography using a private key for encrypting a message and a public key for decrypting the message, the method comprising:

randomly using a different private key/digital certificate pair from a set of valid private key/digital certificate pairs stored on a vehicle to sign or encrypt the message being sent to a wireless system, the wireless system maintaining a pool of currently valid common private key/digital certificate pairs that includes the set of the valid private key/digital certificate pairs;

receiving a certificate revocation list message sent out by the wireless system that contains a list of revoked private key/digital certificate pairs to be revoked; and

replacing a private key/digital certificate pair of the set of stored private key/digital certificate pairs on the vehicle if it is on the certificate revocation list by

contacting a certificate authority and authenticating the vehicle by sending an encrypted vehicle identifier, which is indicative of the vehicle based on at least one of a hardware configuration and a software configuration of the vehicle such that the vehicle identifier changes when the at least one of the hardware configuration and the software configuration changes,

selecting a private key/digital certificate pair from the pool of valid common private key/digital certificate pairs, with each of the private keys in the pool of common private keys being shared by another vehicle, and

receiving and storing on the vehicle a new assigned valid private key/digital certificate pair from the pool of currently valid common private key/digital certificate pairs from the certificate authority.

20. The method of claim 19, wherein

the wireless system is a Dedicated Short Range Communications (DSRC) wireless system.

21. The method of claim 19, wherein

the replacing of the private key/digital certificate pair of the set of stored private key/digital certificate pairs on the vehicle if it is on the certificate revocation list further includes:

sending the encrypted vehicle identifier from the vehicle to the certificate authority;

decrypting the encrypted vehicle identifier at the certificate authority;

authenticating the vehicle against a list of valid vehicle identifiers;

encrypting and sending the selected private key/digital certificate pair to the vehicle; and

decrypting and storing the selected private key/digital certificate pair in the vehicle.

22. The method of claim 19, wherein

the randomly using of the different private key/digital certificate pair from the set of valid private key/digital certificate pairs stored on the vehicle to sign or encrypt the message being sent to the wireless system further includes randomly using the different private key/digital certificate pair from the set of valid private key/digital certificate pairs stored on the vehicle to sign or encrypt the message being sent to a second vehicle.

23. The method of claim 19, wherein

the vehicle identifier is one of a vehicle ID, a VIN, and a configuration key.

24. The method of claim 23, wherein

the configuration key is generated internally by the vehicle from one or more of a VIN, one or more electronic serial numbers (ESNs) of vehicle systems, an identifier of on board equipment, and one or more vehicle software version numbers.

25. The method of claim 19, wherein

each private key/digital certificate pair is a private certificate/digital certificate pair, and

the vehicle generates each private key from the private certificate by utilizing the vehicle identifier.

26. The method of claim 25, wherein

each private key is generated from a stored private certificate utilizing the vehicle identifier by sequentially encrypting or signing an outgoing message with the vehicle identifier and the stored private certificate.

27. The method of claim 25, wherein

each private key is pre-generated for use in encrypting or signing outgoing messages upon vehicle start-up from each private certificate stored in the vehicle utilizing the vehicle identifier.

28. A wireless communication system based on a public-key cryptograph using a private key for encrypting a message and a public key for decrypting the message, the wireless communication system comprising:

a wireless system maintaining a pool of currently valid common private key/digital certificate pairs including a selected set of the valid private key/digital certificate pairs; and

a vehicle adapted to send the message by randomly using a different private key/digital certificate pair from the selected set of valid private key/digital certificate pairs stored on the vehicle to sign the message being sent by the vehicle,

each of the private key/digital certificate pairs in the pool of currently valid common private key/digital certificate pairs being shared by a plurality of vehicles,

the vehicle being further adapted to generate an encrypted vehicle identifier that is indicative of the vehicle based on at least one of a hardware configuration and a software configuration of the vehicle such that the vehicle identifier changes when the at least one of the hardware configuration and the software configuration changes, send a request for the private key/digital certificate pairs including the encrypted vehicle identifier, and receive and store the selected set of private key/digital certificate pairs.

29. The wireless communication system of claim 28, wherein

the wireless system is adapted to revoke a valid private key/digital certificate pair by placing a selected private key/digital certificate pair on a certificate revocation list message sent out by the wireless system.

30. The wireless communication system of claim 29, wherein

the wireless system is adapted to replace a revoked private key/digital certificate pair by authenticating the vehicle to the wireless system by sending a vehicle identifier to a certificate authority to validate the vehicle identity and receiving and storing on the vehicle a new currently valid private key/digital certificate pair from the pool of currently valid common private key/digital certificate pairs.

31. The wireless communication system of claim 28, wherein

the wireless system is a Dedicated Short Range Communications (DSRC) wireless system.

32. A vehicle comprising:

a vehicle component adapted to send a message by randomly using a different private key/digital certificate pair from a set of valid private key/digital certificate pairs stored on the vehicle to sign the message being sent by the vehicle to a wireless system, the wireless system maintaining a pool of currently valid common private key/digital certificate pairs that includes the set of the valid private key/digital certificate pairs, each of the private key/digital certificate pairs in the pool of currently valid common private key/digital certificate pairs being shared by a plurality of vehicles,

the vehicle component being further adapted to generate an encrypted vehicle identifier that is indicative of the vehicle based on at least one of a hardware configuration and a software configuration of the vehicle such that the encrypted vehicle identifier changes when the at least one of the hardware configuration and the software configuration changes, send a request for the private key/digital certificate pairs including the encrypted vehicle identifier, and receive and store the private key/digital certificate pairs selected from the pool of currently valid common private key/digital certificate pairs.

33. The vehicle of claim 32, wherein

the vehicle component is adapted to revoke a valid private key/digital certificate pair by receiving one or more revoked private key/digital certificate pair on a certificate revocation list message sent out by the wireless system.

34. The vehicle of claim 33, wherein

the vehicle component is adapted to replace the revoked private key/digital certificate pair of the set of valid private key/digital certificate pairs by sending the vehicle identifier to a certificate authority to validate the vehicle identity and receiving and storing on the vehicle a new currently valid private key/digital certificate pair from the pool of currently valid common private key/digital certificate pairs.

35. The vehicle of claim 32, wherein

the wireless system is a Dedicated Short Range Communications (DSRC) wireless system.