Memory rewriting system for vehicle controller

• US 7,132,923 B2
• Filed: 03/07/2001
• Issued: 11/07/2006
• Est. Priority Date: 03/16/2000
• Status: Expired due to Term

• Current Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Original Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Inventors: Matsuura, Masanori, Yashiki, Tetsuya, Mizuo, Naohiko
• Primary Examiner(s): Garber, Wendy R.
• Assistant Examiner(s): BANGACHON, WILLIAM L
• Application Number:
  US09/800,814
• Publication Number:
  US 20010023485A1
• Time in Patent Office: 2,071 Days
• Field of Search: 340/5.21, 340/5.62, 340/5.26, 340/5.2, 340 522- 525, 340 1051- 1052, 340/426.35, 340/825.57, 340/5.64, 340/5.72, 340/5.65, 701/1, 701/29, 701/32, 701/35, 701/115, 713/182, 713/189, 713/191, 713/200, 713/2, 380/28, 380/241, 711/103, 711/154, 307/10.2, 307/10, 307/10.1, 307/5, 180/287
• US Class Current: 340/5.21
• CPC Class Codes: G11C 16/102 External programming circuits, e.g. EPROM programmers; In-circuit programming or reprogramming; EPROM emulators

Abstract

A memory rewriting system for a vehicle controller is provided. The system comprises a vehicle controller and an external rewriting device. A vehicle controller comprises a rewritable memory storing first security data. The first security data is used to determine whether rewriting to the rewritable memory is permitted. The rewriting device transfers new security data to the vehicle controller. The vehicle controller deletes the first security data and writes the new security data into the rewritable memory. Rewriting the new security data is performed by a program stored in a non-rewritable memory. Thus, the security data that is used to determine whether rewriting to the rewitable memory is permitted is rewritten with the new security data. Therefore, if the existing security data stored in the vehicle controller is invalidated, the security feature of the vehicle can be recovered. The vehicle may includes an anti-theft system. In this case, rewriting to the rewritable memory is permitted if the anti-theft system permits an operation as to the vehicle.

Claims

1. A vehicle controller comprising,

a rewritable memory configured to store a security function expressible as a first algebraic equation used to authenticate an external rewriting device to determine whether rewriting to the rewritable memory by the external rewriting device is permitted;

a controller configured to initiate an authentication process to authenticate the external rewriting device by comparing a result of the security function with a security feature of the external rewriting device in response to a request from the external rewriting device to rewrite data held by the rewritable memory and upon authenticating the external rewriting device to delete the security function stored in the rewritable memory and to write a new security function into the rewritable memory; and

an interface configured to receive and transmit one or more signals between the controller and the external rewriting device,

wherein the new security function is different from the deleted security function.

2. The vehicle controller of claim 1, wherein a program for deleting the security function and writing the new security function is stored in a non-rewritable memory.

3. The vehicle controller of claim 1, wherein an anti-theft system is connected to the vehicle controller;

and

wherein rewriting to the rewritable memory is permitted if the anti-theft system permits an operation as to the vehicle.

4. The vehicle controller of claim 1, wherein the rewritable memory is implemented in any form of a flash memory, EPROM and EEPROM.

5. The vehicle controller of claim 2, wherein the rewritable memory and the non-rewritable memory are implemented in a single memory.

6. A method for rewriting data stored in a rewritable memory in a vehicle controller, the method comprising;

receiving a result of a second security function expressible as an algebraic equation from an external rewriting device in communication with the vehicle controller,

deleting at the vehicle controller a first security function expressible as an algebraic equation stored in the rewritable memory,

determining whether rewriting to the rewritable memory is permitted by the external rewriting device using a result of the first security function, and

if permitted, writing a third security function expressible as an algebraic equation into the rewritable memory,

wherein the third security function is different from the first security function.

7. The method of claim 6, the deleting the first security function and the writing the third security function are performed by a program stored in a non-rewritable memory mounted on the vehicle controller.

8. The method of claim 6, wherein an anti-theft system is connected to the vehicle controller, and

wherein rewriting to the rewritable memory is permitted if the anti-theft system permits an operation as to the vehicle.

9. The method of claim 6, wherein the external rewriting device stores the second security function;

and

wherein the determination of the permission for rewriting to the rewritable memory comprising;

comparing the first security function with the second security function transferred from the rewriting device;

permitting rewriting to the rewritable memory if the first security function matches the second security function.

10. The method of claim 9, wherein the first security function and the second security function have equivalent expressions;

wherein the determination of the permission for rewriting to the rewritable memory comprising;

calculating a first function value for a number based on the function of the first security data in the vehicle controller;

calculating a second function value for the number based on the function of the second security data in the rewriting device;

comparing the first function value with the second function value; and

permitting the rewriting device to rewrite to the rewritable memory if the first function value is equal to the second function value.

11. A memory rewriting system for a vehicle controller comprising:

a vehicle controller comprising a rewritable memory, the rewritable memory storing second security data; and

a rewriting device for storing first security data,

wherein the vehicle controller is configured to;

determine whether there is a predetermined relationship between the first security data received from the rewriting device and the second security data stored in the rewritable memory;

release a security feature that prevents the rewritable memory from being rewritten if it is determined that there is the predetermined relationship therebetween;

delete the second security data after release of the security feature; and

write third security data received from the rewriting device, different from the first security data, into the rewritable memory,

the rewriting device being suitable for additionally storing the third security data.