Secure memory device with unique identifier for authentication

1. A secure memory device for secure data storage, comprising:

an accessible data storage area configured to store data;

a secret area comprising a device secret that is a value unique to the secure memory device, where the secret area comprises read-only memory (ROM);

an access control element comprise of one or more processors configured to control access to the device secret in the secret area, where the access is controlled by a switch to govern access to the secret area such that access is controlled for components that are internal to the secure memory device and for components that are external to the secure memory device, wherein the access control element allows access to the secret area based on an allow access command, and wherein the allow access command allows access to the secret area in an exclusive mode which allows only one operation to run on the secure memory device;

a generator that generates a derived secret based on the data stored in the accessible data storage area and the device secret stored in the secret area, where the derived secret forms the basis of authenticated communication between the secure memory device and an external device for operations on the accessible data storage area, wherein the generator is a component internal to the secure memory device, and wherein the switch is disposed between the secret area and the generator to control access to the secret area for the generator; and

a memory bus over which the derived secret is communicated to the external device.

2. The secure memory device of claim 1 , where the device secret is established at the time of manufacture of the secure memory device.

3. The secure memory device of claim 1 , where the device secret is retained by at least one of fuses and antifuses.

4. The secure memory device of claim 1 , where the device secret is stored in flash memory cells.

5. The secure memory device of claim 1 , where the access control element is configured to allow access to the device secret only when the generator is accessing the secret area to generate the derived secret and to disallow access at other times.

6. The secure memory device of claim 1 , where the access control element disallows access to the secret based on a disallow access command.

7. The secure memory device of claim 1 , where the access control element disallows access to the secret area based on a predefined criteria.

8. The secure memory device of claim 1 , where the derived secret is used in an keyed-hash message authentication code (HMAC) session key between the secure memory device and the external device.

9. The secure memory device of claim 1 , where the secure memory device is constructed using NOR logic flash memory.

10. The secure memory device of claim 1 , where the secure memory device is constructed as flash memory.

11. The secure memory device of claim 1 , further comprising:

a start location register that points to a start of the accessible data storage area; and a size-related register that allows a size of the accessible data storage area to be determined.

12. The secure memory device of claim 1 , further comprising:

general purpose registers that layer address spaces to other chip registers.

13. A method for operating a secure memory device for secure data storage, comprising:

storing a device secret in a secret area of the secure memory device, the device secret being a value that is unique to the secure memory device, where the secret area comprises read-only memory (ROM);

storing storage data in an accessible data storage area of the secure memory device;

allowing, by an access control element comprise of one or more processors, a generator of the secure memory device access to the device secret, wherein the access control element is a switch that governs access to the secret area of the secure memory device such that access is controlled for components that are internal to the secure memory device and for components that are external to the secure memory device, wherein the access control element allows access to the secret area based on an allow access command, and wherein the allow access command allows access to the secret area in an exclusive mode which allows only one operation to run on the secure memory device;

generating, by the generator, a derived secret based on the storage data stored in the accessible data storage area and the device secret stored in the secret area, where the derived secret forms the basis of authenticated communication between the secure memory device and an external entity for operations on the accessible data storage area, wherein the generator is a component internal to the secure memory device, and wherein the switch is disposed between the secret area and the generator to control access to the secret area for the generator; and

communicating the derived secret to the external entity over a memory bus.

14. The method of claim 13 , further comprising:

allowing access to the device secret by the access control element only when the generator accesses the device secret to generate the derived secret; and

disallowing access at other times.

15. The method of claim 13 , where the generator uses a keyed-hash message authentication code (HMAC) to generate the derived secret.

16. The method of claim 13 , further comprising: responding to a comparison of the generated derived secret based on a previously calculated derived secret that identifies that the generated derived secret is equal to the previously calculated derived secret by performing a normal memory read operation.

17. The method of claim 13 , further comprising: responding to a comparison of the generated derived secret based on a previously calculated derived secret that identifies that the generated derived secret is not equal to the previously calculated derived secret, then performing an exception operation.

18. The method of claim 13 , further comprising using a unique session key to authenticate the secure memory device messages or commands.

19. A non-transitory computer-readable medium comprising instructions thereon that, when executed by a computing device, cause the computing device to perform operations comprising:

storing a device secret in a secret area of a secure memory device, the device secret being a value that is unique to the secure memory device, where the secret area comprises read-only memory (ROM);

storing storage data in an accessible data storage area of the secure memory device;

allowing, by an access control element comprise of one or more processors, a generator of the secure memory device access to the device secret in the secret area, where the access control element being a switch disposed between the secret area and the generator, wherein the access control element allows access to the secret area based on an allow access command, and wherein the allow access command allows access to the secret area in an exclusive mode which allows only one operation to run on the computing device;

generating, by the generator, a derived secret based on the storage data and the device secret, where the derived secret forms the basis of authenticated communication between the secure memory device and an external entity for operations on the accessible data storage area; and

communicating the derived secret to the external entity over a memory bus.

20. The non-transitory computer readable medium of claim 19 , where the operations further comprise:

responding to a comparison of the generated derived secret based on a previously calculated derived secret; and

when the comparison result is that the generated derived secret is equal to the previously calculated derived secret, then performing a normal continued operation; and

when the comparison result is that the generated derived secret is not equal to the previously calculated derived secret, then performing an exception operation.

21. The non-transitory computer readable medium of claim 19 , where the operations further comprise:

allowing access to the device secret by the access control element only when the generator accesses the device secret to generate the derived secret; and

disallowing access at other times.

22. A host system apparatus, comprising:

a processor; and

a secure memory device in communication with the processor, the secure memory device comprising:

an accessible data storage area configured to store data;

a secret area comprising a device secret that is a value unique to the secure memory device, where the secret area comprises read-only memory (ROM);

an access control element comprise of one or more processors configured to control access to the device secret in the secret area, where the access is controlled by a switch to govern access to the secret area such that access is controlled for components that are internal to the secure memory device and for components that are external to the secure memory device, wherein the access control element allows access to the secret area based on an allow access command, and wherein the allow access command allows access to the secret area in an exclusive mode which allows only one operation to run on the secure memory device;

a generator that generates a derived secret based on the data stored in the accessible data storage area and the device secret stored in the secret area, where the derived secret forms the basis of authenticated communication between the secure memory device and an external device for operations on the accessible data storage area, where the external device is external to the secure memory device, wherein the generator is a component internal to the secure memory device, and wherein the switch is disposed between the secret area and the generator to control access to the secret area for the generator; and

a memory bus over which the derived secret is communicated to the external device.

23. The host system apparatus of claim 22 , wherein the host system apparatus is a portion of an automobile.

24. The host system apparatus of claim 22 , wherein the host system apparatus is a portion of an internet of things appliance.