Verifier for remotely verifying integrity of memory and method thereof

• US 7,444,561 B2
• Filed: 01/12/2006
• Issued: 10/28/2008
• Est. Priority Date: 02/23/2005
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Lee, Kyung-hee, Korkishko, Tymur
• Primary Examiner(s): Chung; Phung M
• Application Number:
  US11/330,093
• Publication Number:
  US 20060190798A1
• Time in Patent Office: 1,020 Days
• Field of Search: 714/758, 714/718, 714/6, 714/807, 714/752, 714/746, 714/819, 714/736, 717/136, 717/106, 713/156, 726/9
• US Class Current: 714/718
• CPC Class Codes: G06F 11/08 Error detection or correction by redundancy in data representation, e.g. by using checking codes

Abstract

A verifier for remotely checking integrity of a device connected via a network, includes a calculator which fills free areas in a memory of the device with random numbers and generates a local check code; an interface which transmits integrity check parameters that are used by the device to generate a remote check code, to the device, and receiving the remote check code from the device; a determiner which detects a remote check code generation time and compares the detected remote check code generation time with a presorted remote check code generation expectation time; and a controller which confirms the integrity of the memory of the device when the remote check code generation time does not exceed the remote check code generation expectation time according to a result of the determination and the local check code matches the remote check code.

Claims

1. A verifier which remotely checks an integrity of a device connected via a network, the verifier comprising:

a calculator which fills free areas in a memory of the device with random numbers based on a prestored memory filling map and generates a local check code used to check the integrity of the memory;

an interface which transmits integrity check parameters which are used by the device to generate a remote check code used to check the integrity the memory, to the device, and receives the remote check code from the device;

a determiner which detects a remote check code generation time by measuring a difference between a transmission time of the integrity check parameters and a reception time of the remote check code and compares the detected remote check code generation time with a prestored remote check code generation expectation time; and

a controller which confirms the integrity of the memory of the device if the remote check code generation time does not exceed the remote check code generation expectation time according to a result of the comparison by the determiner and the local check code matches the remote check code.

2. The verifier according to claim 1, wherein the local check code and the remote check code are generated using a message authentication code (MAC).

3. The verifier of claim 2, wherein the calculator generates the local check code by reading out the contents in the memory in a reverse order and applying an MAC generation function.

4. The verifier of claim 2, wherein the device comprises:

an interface which receives the integrity check parameters and transmits the generated remote check code to the verifier;

a central processing unit (CPU) which stores an MAC generation function used to generate the local check code; and

a generator which generates the remote check code using the received integrity check parameters and the MAC generation function.

5. The verifier of claim 4, wherein the integrity check parameters comprise the random numbers and the memory filling map which is used to fill out the free areas in the memory with the random numbers.

6. The verifier of claim 5, wherein the generator generates the remote check code by filling the free areas in the memory with the random numbers based on the memory filling map and applying the MAC generation function while reading out the contents in the memory in a reverse order.

7. The verifier of claim 1, further comprising:

a storage which stores contents of the memory of the device, the random numbers, the memory filling map, and the remote check code generation expectation time.

8. The verifier of claim 1, further comprising:

a random number generator which generates the random numbers to fill out the free areas in the memory by use of a random function.

9. The verifier of claim 1, wherein the controller determines an integrity check failure of the memory of the device if the remote check code generation time exceeds the remote check code generation expectation time according to a result of the comparison.

10. The verifier of claim 1, wherein the remote check code generation expectation time is an average time taken to generate the remote check code if the integrity of the memory of the device is verified.

11. The verifier of claim 1, wherein the controller checks the integrity of the memory by comparing the local check code and the remote check code if the determiner determines that remote check code generation time exceeds the remote check code generation expectation time but does not exceed a presorted threshold delay time.

12. A system comprising:

a device; and

a verifier which is communicatively connected to the device via a network and remotely verifies an integrity of a memory,

wherein the verifier fills out free areas in the memory with random numbers, generates a local check code to check the integrity of the memory, and checks the integrity of the memory by determining whether the local check code matches a remote check code for the integrity check of the memory, and that a remote check code generation time does not exceed a remote check code generation expectation time, and

wherein the device generates the remote check code by receiving and using information used to generate the local check code.

13. The system of claim 12, wherein the verifier comprises:

a calculator which fills the free areas in the memory with the random numbers based on a presorted memory filling map and generates the local check code for the integrity check of the memory;

an interface which transmits integrity check parameters that are used by the device to generate the remote check code for the integrity check of the memory, to the device, and receives the remote check code from the device;

a determiner which detects the remote check code generation time by measuring a transmission time of the integrity check parameters and a reception time of the remote check code and compares the detected remote check code generation time with a presorted remote check code generation expectation time; and

a controller which confirms the integrity of the memory if the remote check code generation time does not exceed the remote check code generation expectation time according to a result of the comparison by the determiner and the local check code matches the remote check code.

14. The system of claim 12, wherein the device comprises:

an interface which receives the information used to generate the local check code and transmits the generated remote check code to the verifier;

a CPU which stores an MAC generation function used to generate the local check code; and

a generator which generates the remote check code using the received information used to generate the local check code and the MAC generation function.

15. The system according to claim 12, wherein the local check code and the remote check code are generated using a message authentication code (MAC).

16. A method which remotely verifies an integrity of a device that is connected via network using a verifier, the method comprising:

filling free areas in a memory of the device with random numbers based on a prestored memory filling map and generating a local check code for the integrity check of the memory;

transmitting integrity check parameters that are used by the device to generate a remote check code for the integrity check of the memory, to the device, and receiving the remote check code from the device;

detecting a remote check code generation time by measuring a transmission time of the integrity check parameters and a reception time of the remote check code and comparing the detected remote check code generation time with a presorted remote check code generation expectation time; and

confirming the integrity of the memory of the device if the remote check code generation time does not exceed the remote check code generation expectation time according to a result of the comparison and the local check code matches the remote check code.

17. The method according to claim 16, wherein the local check code and the remote check code are generated using a message authentication code (MAC).

18. The method of claim 17, wherein the local check code is generated by reading out the contents in the memory in a reverse order and applying an MAC generation function.

19. The method of claim 16, further comprising:

storing contents of the memory of the device, the random numbers, the memory filling map, and the remote check code generation expectation time.

20. The method of claim 16, further comprising:

generating the random numbers to fill out the free areas in the memory by use of a random function.

21. The method of claim 16, wherein the integrity confirmation determines the integrity check failure of the memory of the device if the remote check code generation time exceeds the remote check code generation expectation time according to a result of the determination.

22. The method of claim 16, wherein the remote check code generation expectation time is an average time taken to generate the remote check code if the integrity of the memory of the device is verified.

23. The method of claim 16, wherein the integrity of the memory is checked by comparing the local check code and the remote check code if a determination is made that remote check code generation time exceeds the remote check code generation expectation time but does not exceed a presorted threshold delay time.

24. The method of claim 16, wherein the integrity check parameters comprise the random numbers and the memory filling map which is used to fill the free areas in the memory with the random numbers.

25. A method for remotely verifying integrity of a memory by use of a system comprising a device and a verifier which is communicatively connected to the device via a network and remotely checks the integrity of a memory, the method comprising:

filling, by the verifier, free areas in a memory of the device with random numbers based on a presorted memory filling map and generating a local check code for the integrity check of the memory;

transmitting, by the verifier, integrity check parameters used by the device to generate a remote check code for the integrity check of the memory, to the device and measuring a transmission time of the integrity check parameters;

generating, by the device, the remote check code using the received integrity check parameters and transmitting the generated remote check code to the verifier;

detecting, by the verifier, a remote check code generation time by receiving the remote check code and measuring a reception time of the remote check code, and comparing the remote check generation time with a presorted remote check code generation expectation time; and

confirming, by the verifier, the integrity of the memory of the device if the remote check code generation time does not exceed the remote check code generation expectation time according to a result of the comparison and the local check code matches the remote check code.

26. The method according to claim 25, wherein the local check code and the remote check code are generated using a message authentication code (MAC).