Local digital network, methods for installing new devices and data broadcast and reception methods in such a network

• US 9,210,137 B2
• Filed: 08/23/2002
• Issued: 12/08/2015
• Est. Priority Date: 08/24/2001
• Status: Expired due to Fees

• Current Assignee: Thomson Licensing SA (Vantiva SA)
• Original Assignee: Thomson Licensing (Vantiva SA)
• Inventors: Diehl, Eric, Andreaux, Jean-Pierre, Durand, Alain
• Primary Examiner(s): Holder, Bradley
• Application Number:
  US10/487,489
• Publication Number:
  US 20050278524A1
• Time in Patent Office: 4,855 Days
• Field of Search: 713168-170, 713/189, 713/150, 713/181, 380277-278, 380/210, 380/211, 380/280, 725/31, 705/51
• US Class Current: 1/1
• CPC Class Codes: H04L 2209/601 Broadcast encryption
• CPC Class Codes: H04L 63/0428 wherein the data content is protected, e.g. by encrypting or encapsulating the payload
• CPC Class Codes: 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
• CPC Class Codes: H04L 9/0822 using key encryption key
• CPC Class Codes: H04L 9/088 Usage controlling of secret information, e.g. techniques for restricting cryptographic keys to pre-authorized uses, different access levels, validity of crypto-period, different key- or password length, or different strong and weak cryptographic algorithms network architectures or network communication protocols for using time-dependent keys in a packet data network H04L63/068
• CPC Class Codes: H04L 9/3239 involving non-keyed hash functions, e.g. modification detection codes [MDCs], MD5, SHA or RIPEMD
• CPC Class Codes: H04N 21/4181 for conditional access
• CPC Class Codes: H04N 21/4345 Extraction or processing of SI, e.g. extracting service information from an MPEG stream
• CPC Class Codes: H04N 21/43615 Interfacing a Home Network, e.g. for connecting the client to a plurality of peripherals home Audio Video Interoperability [HAVI] data switching networks H04L12/2805
• CPC Class Codes: H04N 21/4367 Establishing a secure communication between the client and a peripheral device or smart card
• CPC Class Codes: H04N 21/4405 involving video stream decryption
• CPC Class Codes: H04N 21/4408 involving video stream encryption, e.g. re-encrypting a decrypted video stream for redistribution in a home network
• CPC Class Codes: H04N 21/4623 Processing of entitlement messages, e.g. ECM [Entitlement Control Message] or EMM [Entitlement Management Message] arrangements for conditional access to broadcast information or to broadcast-related services H04H60/14
• CPC Class Codes: H04N 7/1675 Providing digital key or authorisation information for generation or regeneration of the scrambling sequence pseudo-random number generators in general G06F7/58

Abstract

The invention relates to a local digital network comprising:

• • at least one source device intended to broadcast data over the network; and
  • at least one receiver device intended to receive said data.

The source device uses a network active encryption key to encrypt data liable to be broadcast in the network and the receiver device contains:

• • a network active decryption key for decrypting data encrypted using said active encryption key and
  • at least one decryption key of the network for decrypting data encrypted with the aid of an encryption key used previously in the network.

The invention also relates to the installing of new devices in such a network as well as the sending of data from a source device to a receiver device.

Claims

1. A method for processing encrypted data in a receiver device linked to a domestic digital network further comprising a source device and a recording device, wherein the receiver device stores a network active decryption key and all decryption keys of the domestic digital network used since a creation of the domestic network and furthermore stores a fingerprint of each stored decryption, each fingerprint being calculated with an aid of a one-way function applied to one of said stored decryption keys,

the method comprising, in the receiver device:

receiving the encrypted data from the source device or the recording device, the encrypted data comprising data encrypted by the source device using a symmetric encryption process with a network active encryption key and a key fingerprint corresponding to the network active encryption key;

extracting said key fingerprint from the data received;

comparing the extracted fingerprint with the stored fingerprints; and

in case of equality between the extracted fingerprint and a stored fingerprint, decrypting the encrypted data with the key corresponding to said fingerprint.