Processing

Please wait...

Settings

Settings

Goto Application

1. WO1985000491 - ENCRYPTED BROADCAST TELEVISION SYSTEM

Publication Number WO/1985/000491
Publication Date 31.01.1985
International Application No. PCT/GB1984/000237
International Filing Date 02.07.1984
IPC
H04N 7/167 2011.01
HELECTRICITY
04ELECTRIC COMMUNICATION TECHNIQUE
NPICTORIAL COMMUNICATION, e.g. TELEVISION
7Television systems
16Analogue secrecy systems; Analogue subscription systems
167Systems rendering the television signal unintelligible and subsequently intelligible
CPC
H04N 21/26613
HELECTRICITY
04ELECTRIC COMMUNICATION TECHNIQUE
NPICTORIAL COMMUNICATION, e.g. TELEVISION
21Selective content distribution, e.g. interactive television or video on demand [VOD]
20Servers specifically adapted for the distribution of content, e.g. VOD servers; Operations thereof
25Management operations performed by the server for facilitating the content distribution or administrating data related to end-users or client devices, e.g. end-user or client device authentication, learning user preferences for recommending movies
266Channel or content management, e.g. generation and management of keys and entitlement messages in a conditional access system, merging a VOD unicast channel into a multicast channel
26613for generating or managing keys in general
H04N 21/6402
HELECTRICITY
04ELECTRIC COMMUNICATION TECHNIQUE
NPICTORIAL COMMUNICATION, e.g. TELEVISION
21Selective content distribution, e.g. interactive television or video on demand [VOD]
60Network structure or processes for video distribution between server and client or between remote clients; Control signalling between clients, server and network components; Transmission of management data between server and client ; , e.g. sending from server to client commands for recording incoming content stream; Communication details between server and client 
63Control signaling ; related to video distribution; between client, server and network components; Network processes for video distribution between server and clients ; or between remote clients; , e.g. transmitting basic layer and enhancement layers over different transmission paths, setting up a peer-to-peer communication via Internet between remote STB's; Communication protocols; Addressing
64Addressing
6402Address allocation for clients
H04N 7/1675
HELECTRICITY
04ELECTRIC COMMUNICATION TECHNIQUE
NPICTORIAL COMMUNICATION, e.g. TELEVISION
7Television systems
16Analogue secrecy systems; Analogue subscription systems
167Systems rendering the television signal unintelligible and subsequently intelligible
1675Providing digital key or authorisation information for generation or regeneration of the scrambling sequence
Applicants
  • INDEPENDENT BROADCASTING AUTHORITY [GB]/[GB] (AllExceptUS)
  • MASON, Arthur, Gordon [GB]/[GB] (UsOnly)
Inventors
  • MASON, Arthur, Gordon
Agents
  • CRAWFORD, Andrew, Birkby @
Priority Data
831779630.06.1983GB
831981722.07.1983GB
Publication Language English (EN)
Filing Language English (EN)
Designated States
Title
(EN) ENCRYPTED BROADCAST TELEVISION SYSTEM
(FR) SYSTEME DE TELEVISION A EMISSION CHIFFREE
Abstract
(EN)
A conditional access system for transmitting and receiving scrambled television signals over-air includes means for addressing each of the receiving apparatus with an over-air signal whereby to permit reception and descrambling of the signal. The transmitter is provided with means for assembling a cipher block of information including a first key for use in descrambling the television signal and information relating to a plurality of users, and means for encyphering the cipher block with a second key which is common to the plurality of users. On reception, a receiver applies the second, common key to the received cipher block, recovers the first key for use in descrambling the signal and the information relating to the respective user and descrambles the television signal. Further, it is proposed to transmit a further key in encrypted form and to use the first key to decrypt the further key which is then used to descramble the television signal. This provides a three level key system which is very secure but by using a common second key for a plurality of users, the time to access each user is short.
(FR)
Un système d'accès conditionnel pour la transmission et la réception de signaux hertziens brouillés de télévision comprend un organe permettant d'envoyer à chaque appareil récepteur un signal hertzien permettant la réception et le débrouillage du signal. L'émetteur est pourvu d'organes permettant d'assembler un bloc de chiffrement d'informations comprenant une première clef destinée à être utilisée dans le débrouillage du signal de télévision et des informations relatives à une pluralité d'utilisateurs, et un organe servant au chiffrement du bloc de chiffre avec une deuxième clef qui est commune à la pluralité d'utilisateurs. Lors de la réception, un récepteur applique la deuxième clef commune au bloc de chiffre reçu, recouvre la première clef nécessaire au débrouillage du signal et des informations relatives à l'utilisateur respectif et débrouille le signal de télévision. On propose en outre de transmettre une clef supplémentaire sous une forme chiffrée et d'utiliser la première clef pour déchiffrer la clef supplémentaire qui est alors utilisée pour débrouiller le signal de télévision. Cela permet d'obtenir un système de clef à trois niveaux qui est très sûr, mais en utilisant une deuxième clef commune pour une pluralité d'utilisateurs, le temps d'accès à chaque utilisateur est court.
Also published as
Latest bibliographic data on file with the International Bureau