Granted Patent B2

US 8,006,095 · App. 11/848,854 · Granted Aug 23, 2011

Abstract

Claims (50)

1. A method, comprising:

retrieving configuration information from a protected first memory, wherein the configuration information specifies a plurality of non-contiguous memory locations, wherein the plurality of non-contiguous memory locations store one or more parameters for a signature formula;

retrieving the one or more parameters for the signature formula from the plurality of non-contiguous memory locations based on the configuration information; and

calculating a first signature formula;

wherein the first signature is useable to verify security for a system.

2. The method of claim 1 , wherein the first signature corresponds to specified data and/or program code stored in a second memory, and wherein the method further comprises:

copying the specified data and/or program code from the second memory to a third memory;

retrieving a second signature wherein said calculating the first signature comprises calculating the first signature for the specified data and/or program code using the signature formula; and

comparing the calculated first signature with the retrieved second signature to verify the specified data and/or program code.

3. The method of claim 2 , wherein the specified data and/or program code comprises initialization code for the system.

4. The method of claim 2 , wherein the system comprises a main processor and an embedded controller, and wherein said copying, said calculating, and said comparing are performed by the embedded controller prior to boot-up of the main processor.

5. The method of claim 2 , wherein the configuration information further comprises the one or more parameters for the signature formula.

6. The method of claim 2 , wherein the first signature comprises one or more of:

a cyclic redundancy check (CRC);

a checksum; or

a hash.

7. The method of claim 2 ,

wherein the protected first memory comprises a register on a chip in the system;

wherein the second memory comprises an external memory located off-chip; and

wherein the third memory comprises a random access memory (RAM) on the chip.

8. The method of claim 2 , wherein the signature formula comprises multi-byte data distributed over the plurality of non-contiguous memory locations in a trailer, and wherein the configuration information specifies the location and order of each byte of the data.

9. The method of claim 8 , wherein the trailer is comprised in the third memory, and wherein, in addition to the plurality of non-contiguous memory locations storing the signature formula, the trailer comprises random values.

10. The method of claim 2 , wherein the first memory, the embedded controller, and the third memory are comprised in a system-on-chip (SoC) in the system.

11. A system for authenticating data or program code, comprising:

an embedded processor; and

a protected first memory coupled to the embedded processor, wherein the protected first memory stores configuration information specifying a plurality of non-contiguous memory locations that store one or more parameters for a signature formula;

wherein the embedded processor is operable to retrieve the one or more parameters for the signature formula from the plurality of non-contiguous memory locations based on the configuration information and to calculate a first signature using the signature formula, wherein the signature is useable to verify security for a system.

12. The system of claim 11 , further comprising:

a second memory coupled to the embedded processor, wherein the second memory stores data and/or program code, and wherein the first signature corresponds to the data and/or program code stored in the second memory; and

a third memory coupled to the embedded processor, wherein the embedded processor is further operable to:

copy the data and/or program code from the second memory to the third memory;

retrieve a second signature

wherein said calculating the first signature comprises calculating the first signature for the data and/or program code using the signature formula; and

compare the calculated first signature with the retrieved second signature to verify the data and/or program code.

13. The system of claim 12 , wherein the data and/or program code comprises initialization code for the system.

14. The system of claim 12 , further comprising:

a main processor, coupled to the embedded processor;

wherein the embedded processor is operable to perform said copying, said calculating, and said comparing prior to boot-up of the main processor.

15. The system of claim 12 , wherein the configuration information further comprises the one or more parameters for the signature formula.

16. The system of claim 12 , wherein the signature comprises one or more of:

a cyclic redundancy check (CRC);

a checksum; or

a hash.

17. The system of claim 12 ,

wherein the protected first memory comprises a register on a chip in the system;

wherein the second memory comprises an external memory located off-chip; and

wherein the third memory comprises a random access memory (RAM) on the chip.

18. The system of claim 12 , wherein the signature formula comprises multi-byte data distributed over the plurality of non-contiguous memory locations in a trailer, and wherein the configuration information specifies the location and order of each byte of the data.

19. The system of claim 18 , wherein the trailer is comprised in the third memory, and wherein, in addition to the plurality of non-contiguous memory locations storing the signature formula, the trailer comprises random values.

20. The system of claim 12 , wherein the first memory, the embedded controller, and the third memory are comprised in a system-on-chip (SoC) in the system.

Assignments (10)