US 7,809,942 B2Granted

Conditional access method and apparatus of a receiver system for controlling digital TV program start time

AssigneeGoBack TV, Inc.

InventorsPaul Baran, Xu Duan Lin, John Pickens, Michael Field

Life of this patent

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Abstract

A conditional access method and apparatus for use with a system for controlling of digital TV program start time. Subscriber access is authorized to digital program streams. Content are divided into a plurality of working periods. Each working period of the plurality of working periods is scrambled with a different working key. A working key of a given period is delivered ahead of the given period. The working key is synchronized with scrambling control bits in an header. working keys are inserted into an entitlement control message (ECM) packet, and the ECM packet is encrypted using a service key. A time period is inserted into the ECM packet during which the service key is valid. A service key is inserted in an entitlement.

Claims14

Dependent claims

A conditional access method for use with a system for controlling of digital television program start time, for authorizing subscriber access to digital program streams, comprising the steps of:

dividing content into a plurality of working periods;
scrambling different working periods of the plurality of working periods with a different working keys, with the working keys synchronized with scrambling control bits in a content packet header;
inserting working keys into entitlement control message (ECM) packets;
encrypting the ECM packet using service keys at a distribution hub that uses quadrature amplitude modulation to deliver at least video on demand to a particular subscriber cluster;
delivering the working keys via a network to subscriber devices ahead of the working periods to which they apply;
inserting, in an entitlement management message (EMM) packet, a service key for decrypting the ECM packets;
encrypting the EMM packet using a user-specific key for an individual subscriber device to which the EMM packet is sent;
periodically sending EMM packets having new service keys usable by a group of individual subscribers from the distribution hub via a network to the subscriber devices, such that the new service keys have a limited distribution area, which reduces incentives for pirating;
and
authenticating the EMM packet with a digital signature of a valid headend.

7 more elements

A conditional access apparatus for use with a system for controlling of digital TV program start time, with for authorizing subscriber access to digital program streams comprising:

a dividing module running on a system that divides content into a plurality of working periods;
a scrambling module that scrambles different working periods using different working keys, with the working keys synchronized with scrambling control bits in a content packet header;
an ECM forming module that inserts working keys into entitlement control message (ECM) packets;
a first encrypting module running on a distribution hub that encrypts the ECM packets using service keys, wherein the distribution hub uses quadrature amplitude modulation to deliver at least video on demand to a subscriber cluster;
an EMM forming module that inserts a service key used to decrypt the ECM packet into an entitlement management message (EMM) packet;
an encrypting and signing module running on a system that encrypts the EMM packet using a user-specific key for an individual subscriber device to which the EMM packet is sent and signs the EMM packet using a key for a valid headend;
an EMM transmitter that periodically sends EMM packets having new service keys from the distribution hub to a group of individual subscribers in the subscribe cluster, whereby the new service keys have a limited distribution area, which reduces incentive for pirating.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application: 11/098,787Filed 5 Apr 2005 · division
Priority: 27 Dec 2001
Published: US 2005/0198680 A18 Sep 2005
Granted: 5 Oct 2010
Term ends: Not estimatedThe source records don’t support an estimate.

Classification22 codes

H04L 63/068
For supporting key management in a packet data network: using time-dependent keys, e.g. periodically changing keys
H04L 63/10
Network architectures or network communication protocols for network security: for controlling access to devices or network resources
H04L 65/612
For supporting one-way streaming services, e.g. Internet radio: for unicast
H04N 7/17318
Transmission or handling of upstream communications: direct or substantially direct transmission and handling of requests

Family

Application60/344,283Us provisional application · filed 27 Dec 2001
Application60/382,174Us provisional application · filed 21 May 2002
Application10/328,868Parent of this division · filed 23 Dec 2002
US 2005/0198680 A1Pre-grant publication · published 8 Sep 2005
US 2003/0200548 A1Published application
US 7,809,942 B2This patent

From the US filing history. Foreign family members aren’t listed.