Method of detecting manipulation of a programmable memory device of a digital controller

• US 8,140,216 B2
• Filed: 03/30/2009
• Issued: 03/20/2012
• Est. Priority Date: 12/28/1999
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Krauter, Immanuel, Moessner, Claus, Aue, Axel
• Primary Examiner(s): Trammell, James P
• Assistant Examiner(s): Shafi, Muhammad
• Application Number:
  US12/414,404
• Publication Number:
  US 20090187305A1
• Time in Patent Office: 1,086 Days
• Field of Search: 701/1, 701/32, 701/54, 701/115, 701/35, 726/2, 726/34
• US Class Current: 701/35
• CPC Class Codes: F02D 41/2425 Particular ways of programming the data
• CPC Class Codes: F02D 41/26 using computer, e.g. microprocessor
• CPC Class Codes: G05B 19/0426 Programming the control sequence
• CPC Class Codes: G05B 2219/24142 Program has a protected, independent part and a free programmable part
• CPC Class Codes: G06F 21/79 in semiconductor storage media, e.g. directly-addressable memories

Abstract

A method of detecting manipulation of a programmable memory device of a digital controller for a motor vehicle is described; data and control programs for operation of the controller and for control/regulation of certain functions of the motor vehicle can be stored in the memory device. To permit especially reliable detection of manipulation in the simplest possible way, in conjunction with each programming/reprogramming operation of the programmable memory device, information regarding the programming/reprogramming operation is stored in a separate memory area of the memory device where only reading and programming are possible, and in order to detect manipulation, the content of the separate memory area is read out and compared with given information.

Claims

1. A method for detecting a manipulation of a programmable memory device of a digital controller for a motor vehicle, the method comprising:

storing in the programmable memory device data and control programs for an operation of the digital controller and for a control/regulation of functions of the motor vehicle;

storing information regarding a programming/reprogramming operation in a separate memory area of the programmable memory device where only reading and programming are possible, wherein the separate memory area is a one-time-programmable (OTP) region of the programmable memory device, the storing of the information regarding the programming/reprogramming operation being performed in conjunction with each programming/reprogramming operation of the programmable memory device, the stored information recording a number of times the programmable memory device has been programmed/reprogrammed; and

reading out and comparing a content of the separate memory area with another set of information in order to detect a manipulation, wherein the separate memory area is incapable of being erased, and wherein a remaining memory area of the programmable memory device is capable of being erased;

wherein the information regarding the programming/reprogramming operation stored in the separate memory area is documented, so that if (i) the motor vehicle enters a workshop and warranty claims are made, or (ii) if the memory of the controller is to be reprogrammed, the content of the separate memory area is read out and compared with a documented information of the memory area, and if the information stored in the separate memory area matches the documented information, then there has not been an unauthorized manipulation of the controller, and if the information read out of the memory area does not match the documented information, then there has been an unauthorized manipulation of the controller.

2. The method according to claim 1, further comprising:

storing in the separate memory area information regarding a cumulative number of programming/reprogramming operations of the programmable memory device.

3. The method according to claim 1, further comprising:

storing in the separate memory area the information regarding the programming/reprogramming operation with each erase operation of the programmable memory device.

4. The method according to claim 1, wherein the information regarding the programming/reprogramming is stored in the separate memory area by setting bits.

5. The method according to claim 1, further comprising:

storing the information regarding the programming/reprogramming in a one-time-programmable region of the programmable memory device, the programmable memory device being arranged as a flash memory.

6. The method according to claim 1, further comprising:

storing in the separate memory area information from an external programming unit for programming/reprogramming a flash memory.

7. The method according to claim 1, further comprising:

storing in the separate memory area information from an arrangement of the digital controller for storing the information regarding the programming/reprogramming operation.

8. The method according to claim 1, wherein the separate memory area has no hardware for performing an erase operation thereon.

9. The method according to claim 1, wherein information regarding the cumulative number of programming/reprogramming operations is stored in the memory area of the programmable memory device, so that with each programming/reprogramming operation, the number stored in the separate memory area is incremented. The number of programming/reprogramming operations is documented. The number stored in the separate memory area can be read out on demand and compared with the documented number. If the two numbers do not match, there has been an undocumented and therefore unauthorized programming/reprogramming operation. According to this refinement, the information stored in the separate memory area is reduced to the minimum amount of data needed to detect unauthorized manipulation of the controller.

10. The method according to claim 9, wherein the information regarding the programming/reprogramming operation is stored in the separate memory area with each erase operation of the programmable memory device, the programmable memory device being erased before programming/reprogramming the control program.

11. The method according to claim 9, wherein the information is stored by setting bits in the separate memory area, an additional bit to be set in the memory area in conjunction with each programming/reprogramming operation to store a cumulative number of programming/reprogramming operations.

12. The method according to claim 9, wherein the information is stored in the one-time-programmable (OTP) region of the programmable memory device, which is a flash EPROM memory, wherein the OTP region involves at least one cell of the flash memory having no line for erasing the content of the flash cells, and wherein the flash cells of the OTP region have only lines for programming or reading the content of the flash cells.

13. The method according to claim 9, wherein:

the information regarding the programming/reprogramming operation is stored in the separate memory area with each erase operation of the programmable memory device, the programmable memory device being erased before programming/reprogramming the control program,

the information is stored by setting bits in the separate memory area, an additional bit to be set in the memory area in conjunction with each programming/reprogramming operation to store a cumulative number of programming/reprogramming operations, and

the information is stored in the one-time-programmable (OTP) region of the programmable memory device, which is a flash EPROM memory, wherein the OTP region involves at least one cell of the flash memory having no line for erasing the content of the flash cells, and wherein the flash cells of the OTP region have only lines for programming or reading the content of the flash cells.