Granted Patent B2

US 7,515,710 · App. 11/685,929 · Granted Apr 7, 2009

Abstract

Claims (54)

1. A content distribution network, comprising:

a registration server including a memory containing a base key, where the registration server is connected to a network;

a content server connected to the network and to a trusted and opaque system, where the trusted and opaque system includes a memory containing the base key and is configured to prevent access to the base key by the content server; and

a playback device including a read only memory containing the base key, and a non-volatile memory, where the playback devices is connected to the network;

wherein the registration server is configured to provide the playback device with unique activation information;

wherein the playback device is configured to store the unique activation information in the non-volatile memory;

wherein the playback device is configured to request content from the content server;

wherein the content server is configured to issue technically protected content including a playback certification;

wherein the content server is configured to obtain the playback certification from the trusted system, where the playback certification includes information enabling playback of the technically protected content that is accessible using the unique activation information and the base key; and

wherein the playback device is configured to use the unique activation information, the base key, and the playback certification to playback the technically protected content.

2. The content distribution network of claim 1 , wherein:

the activation information is protected by the base encryption key and includes a user key and a random value;

the playback device provides the content server with an encrypted copy of the user key that can be accessed using the base key;

the content server provides the encrypted user key and at least one key for accessing the technically protected content to the trusted system; and

the playback certification issued by the trusted system includes encrypted information that is accessible using the base key, and the user key, where the encrypted information includes at least one key for accessing the technically protected content.

3. The content distribution system of claim 2 , wherein the information encrypted using the base key and the user key determines the playback permissions of the technically protected content.

4. The content distribution system of claim 2 , wherein the registration server is configured to revoke the base key.

5. The content distribution system of claim 2 , wherein the registration server is configured to revoke the user key.

6. A content server, comprising:

a processor;

a storage device connected to the processor and including stored content;

a trusted and opaque system connected to the processor, where the trusted and opaque system includes a memory containing base key and is configured to prevent access to the base key; and

a network interface device connected to the processor and configured to be connected to a network;

wherein the processor is configured to receive requests to provide the stored content via the network interface device;

wherein the processor is configured to generate encryption keys and encrypt the stored content;

wherein the processor is configured to provide information indicative of the request and at least one encryption key that can be used to access the encrypted content to the trusted system;

wherein the trusted system is configured to provide a playback certification including encrypted information including an encrypted copy of the at least one encryption key, where at least a portion of the encrypted information in the playback certification is accessible using the base encryption key; and

wherein the processor is configured to transmit the encrypted content and the playback certification via the network interface device.

7. The content server of claim 6 , wherein:

the playback certification includes multiple copies of the at least one encryption key that can be used to access the encrypted content; and

each copy is encrypted using a different encryption key.

8. The content server of claim 6 , wherein:

the trusted system is configured to provide multiple playback certifications;

each playback certification includes at least one encrypted copy of the at least one encryption key that can be used to access the encrypted content; and

each playback certification is formatted differently.

9. A process for issuing technically protected content, comprising:

providing a trusted and opaque system to a content provide, where the trusted and opaque system includes a memory containing a base key and is configured to prevent the content provider from accessing the base key;

encrypting content to be accessible using at least a content key known to the content provider;

providing the content key to the trusted system;

providing playback parameters specified by the content provider to the trusted system;

providing an encrypted user key associated with a device and accessible using the base key to the content provider;

providing the encrypted user key to the trusted system;

decoding the user key using the base key;

receiving a playback certification from the trusted system, where the playback certification including encrypted information, where at least some of the encrypted information is accessible using the base key, at least some of the encrypted information is accessible using the user key, and the encrypted information includes the playback parameters and the content key; and

issuing technically protected content that is accessible using the playback certification, the user key and the base key.

10. The process of claim 9 , further comprising:

receiving multiple user keys and multiple base keys associated with a device and providing the user keys and base keys to the trusted system;

forming a playback parameters table, where each entry in the table includes the playback parameters encrypted using a different base key;

forming a content key table, where each entry in the table includes a copy of the content key encrypted using a different user key;

wherein the playback certification from the trusted system includes encrypted information including the playback parameters table and the content key table.

11. The process of claim 9 , further comprising:

encrypting the playback parameters using the base key; and

encrypting the content key using the user key;

wherein the playback certification from the trusted system includes encrypted information including the encrypted playback parameters and the encrypted content key.

Assignments (10)