Data storage device detecting read-before-write conditions and returning configurable return data

• US 9,164,694 B1
• Filed: 06/19/2013
• Issued: 10/20/2015
• Est. Priority Date: 06/19/2013
• Status: Active Grant

• Current Assignee: JP Morgan Chase Bank, N.A. (JP Morgan Chase & Co)
• Original Assignee: Western Digital Technologies Incorporated (Western Digital Corporation)
• Inventors: Ybarra, Danny O., Gosla, Asif F., Wilkins, Virgil V.
• Primary Examiner(s): BATAILLE, PIERRE MICHE
• Application Number:
  US13/922,099
• Time in Patent Office: 853 Days
• Field of Search: 711/103, 711/163, 711/166, 711/E12.092, 711/E12.008
• US Class Current: 1/1
• CPC Class Codes: G06F 12/1408 by using cryptography for digital transmission H04L9/00
• CPC Class Codes: G06F 21/80 in storage media based on magnetic or optical technology, e.g. disks with sectors preventing unauthorised reproduction or copying of disc-type recordable media G11B20/00
• CPC Class Codes: G06F 2221/2143 Clearing memory, e.g. to prevent the data from being stolen

Abstract

Disclosed herein is a data storage device comprising data storage media comprising a plurality of data sectors and control circuitry programmed to: receive a command from a host to cryptographically erase at least a portion of data stored on the data storage media; execute a cryptographic erase; receive a read command from the host to read a data sector in the data storage media; determine if the data sector has been cryptographically erased; and return configurable return data to the host in response to determining that the data sector has been cryptographically erased.

Claims

1. A data storage device comprising:

data storage media comprising a plurality of data sectors; and

control circuitry programmed to;

receive a command from a host to cryptographically erase at least a portion of data stored on the data storage media;

execute a cryptographic erase;

receive a read command from the host to read a data sector in the data storage media, wherein the read command comprises a logical block address (LBA);

map the LBA to a physical block address (PBA) representing the data sector;

use the PBA to read the data sector from the storage media to generate read data;

decrypt the read data to generate decrypted read data;

execute a data path protection check on the decrypted read data using at least one of the LBA and the PBA;

when the data path protection check fails, determine that the data sector has been cryptographically erased; and

return configurable return data to the host in response to determining that the data sector has been cryptographically erased.

2. The data storage device as recited in claim 1, wherein the control circuitry is further programmed to:

decrypt data stored in the data sector based on a key; and

determine that the data sector has been cryptographically erased when a read-before-write condition is detected.

3. The data storage device as recited in claim 2, wherein the read-before-write condition is detected when the key has been invalidated and no hardware error has been detected.

4. The data storage device as recited in claim 1, wherein the configurable return data comprises scrambled data.

5. The data storage device as recited in claim 4, wherein the control circuitry is further configured to generated the scrambled data by decrypting data written to the data sector with a different key than the one used for encryption prior to writing the data to the data sector.

6. The data storage device as recited in claim 1, wherein the control circuitry is further configured to return a data path protection tag that identifies the returned data as configurable return data instead of data read from the data sector.

7. The data storage device as recited in claim 6, wherein the data storage device supports a Small Computer System Interface (SCSI) and the data path protection tag comprises SCSI T10 protection information.

8. The data storage device as recited in claim 1, wherein the data storage media comprises at least one of:

magnetic recording media; and

solid-state non-volatile memory media.

9. The data storage device as recited in claim 1, wherein the data path protection check comprises generating an error detection code (EDC) over at least part of the decrypted read data based on the LBA received in the read command.

10. A method for managing data in a data storage device that comprises data storage media comprising a plurality of data sectors, the method comprising:

receiving a command from a host to cryptographically erase at least a portion of data stored on the data storage media;

executing a cryptographic erase;

receiving a read command from the host to read a data sector in the data storage media, wherein the read command comprises a logical block address (LBA);

mapping the LBA to a physical block address (PBA) representing the data sector;

using the PBA to read the data sector from the storage media to generate read data;

decrypting the read data to generate decrypted read data;

executing a data path protection check on the decrypted read data using at least one of the LBA and the PBA;

when the data path protection check fails, determining that the data sector has been cryptographically erased; and

returning configurable return data to the host in response to determining that the data sector has been cryptographically erased.

11. The method as recited in claim 10, further comprising:

decrypting data stored in the data sector based on a key; and

determining that the data sector has been cryptographically erased when a read-before-write condition is detected.

12. The method as recited in claim 11, wherein the read-before-write condition is detected when the key has been invalidated and no hardware error has been detected.

13. The method as recited in claim 10, wherein the configurable return data comprises scrambled data.

14. The method as recited in claim 13, further comprising generating the scrambled data by decrypting data written to the data sector with a different key than the one used for encryption prior to writing the data to the data sector.

15. The method as recited in claim 10, wherein returning the configurable return data comprises returning a data path protection tag that identifies the returned data as configurable return data instead of data read from the data sector.

16. The method as recited in claim 15, wherein the data storage device supports a Small Computer System Interface (SCSI) and the data path protection tag comprises SCSI T10 protection information.

17. The method as recited in claim 10, wherein the data storage media comprises at least one of:

magnetic recording media; and

solid-state non-volatile memory media.

18. The method as recited in claim 10, wherein the data path protection check comprises generating an error detection code (EDC) over at least part of the decrypted read data based on the LBA received in the read command.