# US 12,010,372 B2 · Content recording and group encryption

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 12,010,372 B2
- Document ID: US12010372B2
- Status: Granted
- Kind: B2
- Application number: 17/648,286
- Filed: 2022-01-18
- Published: 2022-08-04
- Granted: 2024-06-11
- Earliest claimed: 2018-12-31
- Assignees: Comcast Cable Communications, LLC
- Applicants: Comcast Cable Communications, LLC
- Inventors: Kyong Park
- Web page: https://patentgrep.com/patent/US12010372B2

## CPC

- H04N 21/26613: {for generating or managing keys in general (key distribution for secret or secure communication involving central third party, e.g. key distribution center [KDC] or trusted third party [TTP] H04L9/083; network support of key management H04L63/06; key management for network security in communication control or processing H04W12/04)}
- H04N 21/4147: PVR [Personal Video Recorder] (H04N5/76 takes precedence {; arrangements for broadcast with accumulation-type receivers H04H20/40})
- G06F 21/44: Program or device authentication
- H04L 9/0819: {Key transport or distribution, i.e. key establishment techniques where one party creates or otherwise obtains a secret value, and securely transfers it to the other(s) (network architectures or network communication protocols for key distribution in a packet data network H04L63/062)}
- H04L 9/0822: {using key encryption key}
- H04L 9/0894: {Escrow, recovery or storing of secret information, e.g. secret key escrow or cryptographic key storage}
- H04L 63/0435: {wherein the sending and receiving network entities apply symmetric encryption, i.e. same key used for encryption and decryption (cryptographic mechanisms or cryptographic arrangements for symmetric key encryption H04L9/06)}
- H04L 63/0478: {applying multiple layers of encryption, e.g. nested tunnels or encrypting the content with a first key and then with at least a second key (cryptographic mechanisms or cryptographic arrangements using a plurality of keys or algorithms H04L9/14)}
- H04L 63/062: {for key distribution, e.g. centrally by trusted party (cryptographic mechanisms or cryptographic arrangements for key distribution involving a central third party H04L9/0819)}
- H04N 21/2347: involving video stream encryption
- H04N 21/2541: {Rights Management (protecting software against unauthorised usage in a vending or licensing environment G06F21/10; security in data switching network management H04L41/28; security management or policies for network security H04L63/20; access security in wireless networks H04W12/08)}
- H04N 21/274: Storing end-user {multimedia} data in response to end-user request {, e.g. network recorder}
- G06F 21/1062: {Editing}
- H04L 2209/603: Digital right managament [DRM]
- H04L 2463/062: applying encryption of the keys
- H04L 2463/101: applying security measures for digital rights management
- H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION
- G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N)
- H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M)

## Abstract

Systems and methods for managing group encryption are described. In certain methods, a content asset may be encrypted with an asset key. An account key may be determined. Using the account key, an encrypted content asset package may be generated. The asset key may make up at least a portion of the encrypted content asset package. The encrypted content asset package is decryptable with the account key. The encrypted content asset package and an identifier associated with the account key may be transmitted, for example to a playback device.

## Claims

### Claim 1

A method comprising:
receiving a request for a plurality of content assets, wherein the request comprises a user account identifier;
creating copies of each one of the plurality of content assets, wherein the copies of each one of the plurality of content assets are associated with the user account identifier;
encrypting the copies of each one of the plurality of content assets to generate encrypted copies of each one of the plurality of content assets, wherein a first encrypted copy of one of the plurality of content assets is decryptable with a first asset key, and wherein a second encrypted copy of one of the plurality of content assets is decryptable with a second asset key;
determining an account key associated with the user account identifier;
generating, using the account key, an encrypted content asset package comprising at least the first asset key and the second asset key, wherein the encrypted content asset package is decryptable with the account key; and
transmitting the encrypted content asset package and an identifier associated with the account key.

### Claim 2 (depends on 1)

The method of claim 1, wherein the user account identifier is associated with a premises receiving service from a service provider associated with the copies of each one of the plurality of content assets.

### Claim 3 (depends on 1)

The method of claim 1, wherein the request for the plurality of content assets is received via a user interface of a playback device.

### Claim 4 (depends on 1)

The method of claim 1, wherein the request for the plurality of content assets is received by a network digital video recording system.

### Claim 5 (depends on 1)

The method of claim 1, wherein the account key comprises a time-to-live (TTL).

### Claim 6 (depends on 1)

The method of claim 1, wherein the encrypted content asset package is transmitted to a playback device.

### Claim 7 (depends on 1)

The method of claim 1, wherein the encrypted content asset package comprises the first encrypted copy of one of the plurality of content assets and the second encrypted copy of one of the plurality of content assets.

### Claim 8 (depends on 1)

The method of claim 1, wherein the encrypted content asset package and the identifier associated with the account key are each transmitted in separate communication messages.

### Claim 9

A method comprising:
transmitting, from a content playback device, a request for a plurality of content assets, wherein the request is associated with a user account identifier;
receiving, by the content playback device, an encrypted content asset package and an identifier of an account key, wherein the encrypted content asset package is encrypted using the account key, and wherein the encrypted content asset package comprises an encrypted copy of a first content asset of the plurality of content assets and at least a first asset key usable to decrypt the encrypted copy of the first content asset, and wherein the encrypted content asset package further comprises an encrypted copy of a second content asset of the plurality of content assets and at least a second asset key usable to decrypt the encrypted copy of the second content asset;
determining that the account key is stored on the content playback device;
using the account key stored on the content playback device, decrypting the encrypted content asset package to access the first asset key and the second asset key;
using the first asset key, decrypting the encrypted copy of the first content asset; and
using the second asset key, decrypting the encrypted copy of the second content asset.

### Claim 10 (depends on 9)

The method of claim 9, wherein the user account identifier is associated with a user associated with the content playback device and a service provider.

### Claim 11 (depends on 9)

The method of claim 9, wherein the encrypted content asset package comprises the encrypted copy of the first content asset and the encrypted copy of the second content asset.

### Claim 12 (depends on 9)

The method of claim 9, wherein the identifier of the account key is not encrypted with the account key.

### Claim 13 (depends on 9)

The method of claim 9, wherein the determining the account key is stored on the content playback device comprises searching local storage of the content playback device using the identifier of the account key.

### Claim 14 (depends on 9)

The method of claim 9, further comprising causing display of the decrypted copy of at least one of the first content asset or the second content asset.

### Claim 15

A system comprising: a content playback device; and
a service provider device configured to:
receive, from the content playback device, a request for a plurality of content assets, wherein the request comprises a user account identifier;
create copies of each one of the plurality of content assets, wherein the copies of each one of the plurality of content assets are associated with the user account identifier;
encrypt the copies of each one of the plurality of content assets to generate encrypted copies of each one of the plurality of content assets, wherein a first encrypted copy of one of the plurality of content assets is decryptable with a first asset key, and wherein a second encrypted copy of one of the plurality of content assets is decryptable with a second asset key;
determine an account key associated with the user account identifier;
generate, using the account key, an encrypted content asset package comprising at least the first asset key and the second asset key, wherein the encrypted content asset package is decryptable with the account key; and
transmit the encrypted content asset package and an identifier associated with the account key.

### Claim 16 (depends on 15)

The system of claim 15, wherein the user account identifier is associated with a premises receiving service from a service provider associated with the copies of each one of the plurality of content assets.

### Claim 17 (depends on 15)

The system of claim 15, wherein the request for the plurality of content assets is received via a user interface of the playback device.

### Claim 18 (depends on 15)

The system of claim 15, wherein the account key comprises a time-to-live (TTL).

### Claim 19 (depends on 15)

The system of claim 15, wherein the service provider device is configured to transmit the encrypted content asset package to at least one of the content playback device or a different content playback device.

### Claim 20 (depends on 15)

The system of claim 15, wherein the encrypted content asset package comprises the first encrypted copy of one of the plurality of content assets and the second encrypted copy of one of the plurality of content assets.

### Claim 21 (depends on 15)

The system of claim 15, wherein the encrypted content asset package and the identifier associated with the account key are each transmitted in separate communication messages.

### Claim 22

A system comprising:
a service provider device; and
a content playback device configured to:
transmit a request for a plurality of content assets, wherein the request is associated with a user account identifier;
receive an encrypted content asset package and an identifier of an account key, wherein the encrypted content asset package is encrypted using the account key, and wherein the encrypted content asset package comprises an encrypted copy of a first content asset of the plurality of content assets and at least a first asset key usable to decrypt the encrypted copy of the first content asset, and wherein the encrypted content asset package further comprises an encrypted copy of a second content asset of the plurality of content assets and at least a second asset key usable to decrypt the encrypted copy of the second content asset;
determine that the account key is stored on the content playback device;
decrypting, using the stored account key, the encrypted content asset package to access the first asset key and the second asset key;
decrypting, using the first asset key, the encrypted copy of the first content asset; and
decrypting, using the second asset key, the encrypted copy of the second content asset.

### Claim 23 (depends on 22)

The system of claim 22, wherein the user account identifier is associated with a user associated with the content playback device and wherein the user account identifier is associated with a service provider associated with the service provider device.

### Claim 24 (depends on 22)

The system of claim 22, wherein the encrypted content asset package comprises the encrypted copy of the first content asset and the encrypted copy of the second content asset.

### Claim 25 (depends on 22)

The system of claim 22, wherein the identifier of the account key is not encrypted with the account key.

### Claim 26 (depends on 22)

The system of claim 22, wherein the content playback device is configured to determine the account key is stored on the content playback device, the content playback device further configured to search local storage of the content playback device using the identifier of the account key.

### Claim 27 (depends on 22)

The system of claim 22, wherein the content playback device is further configured to cause display of at least one of the decrypted copy of the first content asset or the decrypted copy of the second content asset.