System and method for securely controlling access to device functions

• US 20030210786A1
• Filed: 05/08/2002
• Published: 11/13/2003
• Est. Priority Date: 05/08/2002
• Status: Active Grant

• Current Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Carr, Jeffrey Douglas
• Granted Patent: US 7,810,152 B2
• Time in Patent Office: Days
• US Class Current: 380/241
• CPC Class Codes: G11C 16/22 Safety or protection circuits preventing unauthorised or accidental access to memory cells
• CPC Class Codes: H04N 21/472 End-user interface for requesting content, additional data or services; End-user interface for interacting with content, e.g. for content reservation or setting reminders, for requesting event notification, for manipulating displayed content end-user interfaces for retrieving video data from a database G06F16/739; network services for supporting unicast streaming H04L65/612
• CPC Class Codes: H04N 21/8453 by locking or enabling a set of features, e.g. optional functionalities in an executable program
• CPC Class Codes: H04N 7/163 by receiver means only

Abstract

Systems and methods that may securely control access to device functions are disclosed. A request is received to enable a feature of the device. In one embodiment, the device may be a set top box, for example. The device determines whether the feature is disabled, whether the feature can be enabled with authorization and whether a requester is authorized to enable the feature of the device. If the feature is disabled, if the feature can be enabled with authorization and if the requester is authorized to enable the feature of the device, then the feature of the device is enabled.

Claims

1. A method for securely controlling access to a feature of a device, comprising the steps of:

(a) receiving a request to enable the feature of the device;

(b) determining whether the feature is disabled;

(c) determining whether the feature can be enabled with authorization;

(e) determining whether a requester is authorized to enable the feature of the device; and

(f) if the feature is disabled, if the feature can be enabled with authorization and if the requestor is authorized to enable the feature of the device, then enabling the feature of the device.

2. The method according to claim 1, wherein step (b) comprises reading a state of mode control bits corresponding to the feature of the device.

3. The method according to claim 2, wherein the step of reading comprises reading the state of the mode control bits on a non-volatile memory.

4. The method according to claim 1, wherein step (c) comprises reading a state of mode control bits corresponding to the feature of the device.

5. The method according to claim 4, wherein the step of reading comprises reading the state of the mode control bits on a non-volatile memory.

6. The method according to claim 1, wherein step (e) comprises:

generating a challenge value by the device,

storing the challenge value,

sending the challenge value to the requestor,

encrypting the challenge value by the requestor,

sending the encrypted challenge value back to the device,

decrypting the encrypted challenge value by the device, and

comparing the stored challenge value with the decrypted challenge value.

7. The method according to claim 6, further including the step of, if the stored challenge value and the decrypted challenge value are equal, then the requestor is authorized.

8. The method according to claim 6, wherein the step of generating the challenge value by the device comprises generating the challenge value as a function of a pseudorandom number.

9. The method according to claim 6, wherein the step of generating the challenge value by the device comprises generating the challenge value as a function of a device identification stored in a non-volatile memory of the device.

10. The method according to claim 6, wherein the challenge value is a Nonce challenge value.

11. The method according to claim 6, wherein the step of encrypting the challenge value by the requester comprises encrypting the challenge value using at least one of a data encryption standard (DES) encryption or a 3-DES encryption.

12. The method according to claim 1, wherein step (e) comprises:

supplying a password to the device,

processing the password by the device,

comparing the processed password with acceptable values, and

if the processed password is one of the acceptable values, then authenticating the password and authorizing the requestor.

13. The method according to claim 12, wherein the step of supplying comprises encrypting a unique device identification with a shared key.

14. The method according to claim 13,

wherein the step of processing the password comprises decrypting the encrypted unique device identification, and

wherein the step of comparing comprises comparing the decrypted identification with the unique device identification stored in a non-volatile memory in the device.

15. The method according to claim 12, wherein the step of processing comprises decrypting the supplied password.

16. The method according to claim 12, wherein the step of encrypting comprises encrypting a data encryption standard (DES) encryption or a 3-DES encryption.

17. A system for securely controlling access to features of a device, comprising:

a non-volatile memory including mode control bits that correspond to the features of the device, the mode control bits indicating whether a particular feature of the device is one of disabled, enabled and capable of being enabled with user authorization; and

a processor coupled to the non-volatile memory, the processor being configured to perform the steps of

receiving a request to enable the particular feature of the device,

determining whether the particular feature is disabled,

determining whether the particular feature can be enabled with the user authorization,

determining whether a user is authorized to enable the particular feature of the device, and

if the particular feature is disabled, if the particular feature can be enabled with the user authorization and if the user is authorized to enable the particular feature of the device, then enabling the particular feature of the device.

18. A system for securely controlling access to a feature of a device, comprising:

means for receiving a request to enable the feature of the device;

means for determining whether the feature is disabled;

means for determining whether the feature can be enabled with authorization;

means for determining whether a requestor is authorized to enable the feature of the device; and

means for enabling the feature of the device if the feature is disabled, if the feature can be enabled with authorization and if the requestor is authorized to enable the feature of the device.