Virtual root of trust for data storage device
A Data Storage Device (DSD) includes a Non-Volatile Memory (NVM) including a private partition with a write-once partition only internally accessed by a controller of the DSD. Data stored in at least one memory of the controller and in the private partition is encrypted. According to one aspect, the NVM includes a firmware partition, and at least one key associated with the DSD stored in the write-once partition is descrambled or decrypted using a scrambler key or decryption key stored in the firmware partition. According to another aspect, a method for establishing a root of trust includes generating a scrambler key or a decryption key, and generating at least one key associated with the DSD. The scrambler key or the decryption key is stored in a firmware partition of an NVM of the DSD, and the at least one key associated with the DSD is stored in a write-once partition.
1. A Data Storage Device (DSD), comprising:
a Non-Volatile Memory (NVM) configured to include a private partition and a public partition, wherein the public partition is configured to store content files, and wherein:
the private partition is configured to include a write-once partition, a secure partition, and a firmware partition,
the write-once partition is configured to store a scrambled or encrypted first root of trust key associated with the DSD and a scrambled or encrypted second root of trust key associated with the DSD, wherein the first root of trust key is distinct from the second root of trust key,
the secure partition is configured to store license keys for accessing the content files stored in the public partition, and
the firmware partition is configured to store a scrambler key or a decryption key; and
a controller including at least one memory, wherein the private partition of the NVM is configured to only be internally accessed by the controller, and wherein the controller is configured to:
descramble or decrypt the scrambled or encrypted first root of trust key using the scrambler key or the decryption key;
encrypt data stored in the at least one memory and in the private partition of the NVM using the first root of trust key, wherein the encrypted data includes the license keys;
descramble or decrypt the scrambled or encrypted second root of trust key using the scrambler key or the decryption key; and
authenticate data stored in the at least one memory and in the private partition using the second root of trust key.
2. The DSD of claim 1 , further comprising a host interface for communicating with a host, and wherein the controller is further configured to restrict the host's access to the NVM to data stored in the public partition of the NVM.
3. The DSD of claim 1 , wherein the controller is further configured to control access to the NVM based on an allowed set of commands included in a firmware stored in the at least one memory of the controller or in the private partition of the NVM.
4. The DSD of claim 1 , wherein the controller and the NVM are sealed together in a multi-die package.
5. The DSD of claim 1 , wherein the DSD is a removable memory card that can interface with a card reader of another electronic device.
6. A Data Storage Device (DSD), comprising:
a Non-Volatile Memory (NVM) configured to include a firmware partition, a public partition for storing content files, a secure partition for storing license keys for accessing the content files stored in the public partition, and a write-once partition configured to be written to only once; and
a controller configured to:
descramble or decrypt a scrambled or encrypted first root of trust key for the DSD that is stored in the write-once partition using a scrambler key stored in the firmware partition or a decryption key stored in the firmware partition;
descramble or decrypt a scrambled or encrypted second root of trust key for the DSD that is stored in the write-once partition using the scrambler key stored in the firmware partition or the decryption key stored in the firmware partition, wherein the first root of trust key is distinct from the second root of trust key;
encrypt at least one other key stored in the firmware partition using the first root of trust key;
encrypt license keys stored in the secure partition using the first root of trust key; and
authenticate the at least one other key stored in the firmware partition using the second root of trust key.
7. The DSD of claim 6 , wherein:
the NVM includes a private partition for storing the firmware partition and the write-once partition; and
the private partition is configured to only be internally accessed by the controller.
8. The DSD of claim 6 , wherein the controller is further configured to encrypt at least one additional key stored in the firmware partition using the descrambled or decrypted first root of trust key associated with the DSD that is stored in the write-once partition.
9. The DSD of claim 6 , wherein:
the DSD further comprises a host interface for communicating with a host; and
the controller is further configured to restrict the host's access to the NVM to data stored in the public partition of the NVM.
10. The DSD of claim 6 , wherein the controller is further configured to control access to the NVM based on an allowed set of commands included as part of a firmware stored in at least one memory of the controller or in the private partition.
11. The DSD of claim 6 , wherein the controller and the NVM are sealed together in a multi-die package.
12. The DSD of claim 6 , wherein the DSD is a removable memory card that can interface with a card reader of another electronic device.
13. A method for establishing a root of trust in a Data Storage Device (DSD), the method comprising:
creating a public partition in a Non-Volatile Memory (NVM) of the DSD, the public partition for storing content files;
creating a secure partition in the NVM for storing license keys for accessing the content files stored in the public partition;
generating a scrambler key or a decryption key;
generating a first root of trust key associated with the DSD;
generating a second root of trust key associated with the DSD, wherein the first root of trust key is distinct from the second root of trust key;
storing the scrambler key or the decryption key in a firmware partition of the NVM;
scrambling the first and the second root of trust keys using the scrambler key or encrypting the first and the second root of trust keys using an encryption key associated with the decryption key, wherein the decryption key is a symmetric or asymmetric key for the encryption key; and
storing the scrambled or encrypted first and second root of trust keys associated with the DSD in a write-once partition of the NVM configured to be written to only once, wherein the first root of trust key is used to encrypt the license keys and data for storage in the firmware partition and the second root of trust key is used to authenticate data stored in the firmware partition.
14. The method of claim 13 , further comprising:
creating a private partition in the NVM; and
configuring the DSD so that the private partition can only be internally accessed by a controller of the DSD.
15. The method of claim 13 , further comprising:
creating a private partition in the NVM; and
encrypting data stored in the private partition using the first root of trust key associated with the DSD.
16. The method of claim 13 , further comprising:
configuring the DSD to restrict external access of the DSD to data stored in the public partition of the NVM.
17. A Data Storage Device (DSD), comprising:
a Non-Volatile Memory (NVM) configured to include a firmware partition, a public partition for storing content files, a secure partition for storing license keys for accessing the content files, and a write-once partition configured to be written to only once; and
means for:
descrambling or decrypting a scrambled or encrypted first root of trust key for the DSD that is stored in the write-once partition using a scrambler key stored in the firmware partition or a decryption key stored in the firmware partition;
descrambling or decrypting a scrambled or encrypted second root of trust key for the DSD that is stored in the write-once partition using the scrambler key stored in the firmware partition or the decryption key stored in the firmware partition, wherein the first root of trust key is distinct from the second root of trust key;
encrypting at least one other key stored in a private partition of the NVM using the first root of trust key;
encrypting the license keys using the first root of trust key; and
authenticating the at least one other key stored in the private partition using the second root of trust key.
18. The DSD of claim 1 , wherein the data encrypted using the first root of trust key includes at least one other key stored in the private partition.