Nonvolatile memory internal signature generation
View Patent ↗A nonvolatile memory device generates a signature using a private key and contents within the memory device. The signature is stored in a secure area within the nonvolatile memory device. A processor having the same private key also generates a signature that is stored in the clear. The processor validates the contents of the nonvolatile memory by comparing the signatures.
1. A method comprising:
receiving an external signature for data stored within a nonvolatile memory device from an external device;
storing the external signature for the data in the clear within the nonvolatile memory device;
generating, by a controller within the nonvolatile memory device storing the data, a signature from the data stored within the nonvolatile memory device, wherein the signature is generated based on the data and a private key stored within a secure storage area of the nonvolatile memory device;
storing the signature in a secure storage area within the nonvolatile memory device; and
providing the signature from the secure area and the external signature to the external device when requested, wherein the signature in the secure storage area is compared with the external signature to validate the data.
2. The method of claim 1 further comprising:
accepting at the nonvolatile memory device changes to the data stored within the nonvolatile memory device; and
updating the signature to reflect the changes.
3. The method of claim 1 wherein generating a signature comprises generating a signature using a secure hash algorithm.
4. The method of claim 1 wherein generating a signature comprises generating a signature using a private key.
5. The method of claim 1 wherein generating a signature within a nonvolatile memory device comprises generating a signature within a phase change memory (PCM) device.
6. The method of claim 1 wherein generating a signature within a nonvolatile memory device comprises generating a signature within a FLASH memory device.
7. A nonvolatile memory device having instructions stored thereon that when executed by a controller within the nonvolatile memory device cause the controller to:
receive and store in the clear an externally generated signature for data stored within the nonvolatile memory device, wherein the externally generated signature is received from a device external to the nonvolatile memory device;
generate a signature from a private key and the data stored within the nonvolatile memory device, wherein the private key is stored in a secure storage area within the nonvolatile memory device;
store the signature in the secure storage area within the nonvolatile memory device; and
provide the signature and the externally generated signature from the secure storage area to the device external to the nonvolatile memory device when requested, wherein the signature provided from the secure storage area is compared to the externally generated signature to validate the data.
8. The nonvolatile memory device of claim 7 wherein the instructions when executed, further cause the controller to:
accept at the nonvolatile memory device changes to the data stored within the nonvolatile memory device; and
update the signature to reflect the changes.
9. The nonvolatile memory device of claim 7 wherein generating a signature comprises generating a signature using a secure hash algorithm.
10. The nonvolatile memory device of claim 7 wherein the nonvolatile memory device comprises a phase change memory (PCM) device.
11. The nonvolatile memory device of claim 7 wherein the nonvolatile memory device comprises a FLASH memory device.
12. A nonvolatile memory device comprising:
a nonvolatile memory array accessible by a device external to the nonvolatile memory device and configured to store in the clear an externally generated signature for data stored in the nonvolatile memory array, wherein the externally generated signature is received from the device external to the nonvolatile memory device;
a nonvolatile secure storage area not accessible by devices external to the nonvolatile memory device; and
a controller configured to secure the secure storage area and to generate a signature from a private key and contents of the nonvolatile memory array, and to store the signature in the secure storage area, the controller further configured to provide the signature and the externally generated signature to the external device responsive to a request, wherein the signature in the secure storage area is compared to the externally generated signature to validate the contents of the nonvolatile memory array.
13. The nonvolatile memory device of claim 12 further comprising:
a microcode store accessible by the controller, the microcode store including instructions to cause the controller to update the signature when changes are made to the contents of the nonvolatile memory array.
14. The nonvolatile memory device of claim 12 wherein the controller implements a secure hash algorithm to generate the signature.
15. The nonvolatile memory device of claim 12 wherein the key is a private key stored in the secure storage area.
16. The nonvolatile memory device of claim 12 wherein the nonvolatile memory array comprises phase change memory (PCM).
17. The nonvolatile memory device of claim 12 wherein the nonvolatile memory array comprises FLASH memory.