Methods for accessing content based on a session ticket

• US 8,533,807 B2
• Filed: 11/18/2011
• Issued: 09/10/2013
• Est. Priority Date: 11/14/2006
• Status: Active Grant

• Current Assignee: SanDisk Technologies LLC (Western Digital Corporation)
• Original Assignee: Sandisk Technologies Incorporated (Western Digital Corporation)
• Inventors: Jogand-Coulomb, Fabrice, Tanik, Haluk Kent, Rasizade, Oktay
• Primary Examiner(s): REVAK, CHRISTOPHER A
• Application Number:
  US13/300,306
• Publication Number:
  US 20120137355A1
• Time in Patent Office: 662 Days
• Field of Search: None
• US Class Current: 726/10
• CPC Class Codes: H04L 2209/603 Digital right managament [DRM]
• CPC Class Codes: H04L 9/0894 Escrow, recovery or storing of secret information, e.g. secret key escrow or cryptographic key storage

Abstract

A method for accessing content stored on a memory device is provided. In this method, a request to access the content is transmitted and a session ticket is received. The session ticket includes a parameter used to decrypt the content and the session ticket is generated based on a variable that is configured to change at a session. The content may be accessed based on the session ticket.

Claims

1. A method for accessing content stored on a memory device, comprising:

generating a session ticket by encrypting a parameter associated with the cryptographic key with a variable that has a value associated with a session and that changes value at different sessions;

providing the session ticket to a host computing device;

receiving the session ticket and a request to access the content from the host computing device;

attempting to extract the parameter associated with the cryptographic key from the session ticket by decrypting the session ticket with the variable, wherein if the session has not changed, the value of the variable has not changed, and the parameter associated with the cryptographic key is extracted from the session ticket; and

if the parameter associated with the cryptographic key is extracted from the session ticket;

obtaining the cryptographic key based on the parameter,

decrypting the content using the cryptographic key, and

sending the content to the host computing device.

2. The method of claim 1, wherein the parameter is a cryptographic nonce, the cryptographic nonce being used to generate a cryptographic key.

3. The method of claim 1, wherein the variable is a number.

4. The method of claim 3, wherein the number is configured to change randomly.

5. The method of claim 1, wherein the session spans for a period of time.

6. The method of claim 1, wherein the session expires when the host computing device is restarted.

7. The method of claim 1, wherein the session expires when the memory device is decoupled from the host computing device.

8. A memory device comprising:

a memory; and

a controller in communication with the memory, wherein the controller is configured to;

generate a session ticket by encrypting a parameter associated with the cryptographic key with a variable that has a value associated with a session and that changes value at different sessions;

provide the session ticket to a host computing device;

receive the session ticket and a request to access the content from the host computing device;

attempt to extract the parameter associated with the cryptographic key from the session ticket by decrypting the session ticket with the variable, wherein if the session has not changed, the value of the variable has not changed, and the parameter associated with the cryptographic key is extracted from the session ticket; and

if the parameter associated with the cryptographic key is extracted from the session ticket;

obtain the cryptographic key based on the parameter,

decrypt the content using the cryptographic key, and

send the content to the host computing device.

9. The memory device of claim 8, wherein the parameter is a cryptographic nonce, the cryptographic nonce being used to generate a cryptographic key.

10. The memory device of claim 8, wherein the variable is a number.

11. The memory device of claim 10, wherein the number is configured to change randomly.

12. The memory device of claim 8, wherein the session spans for a period of time.

13. The memory device of claim 8, wherein the session expires when the host computing device is restarted.

14. The memory device of claim 8, wherein the session expires when the memory device is decoupled from the host computing device.