Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Scientific AtlantafiledCriticalScientific Atlanta
Priority to MX9201397ApriorityCriticalpatent/MX9201397A/en
Publication of MX9201397ApublicationCriticalpatent/MX9201397A/en
Two-Way Televisions, Distribution Of Moving Picture Or The Like
(AREA)
Abstract
Un decodificador para decodificar transmisiones vía satélite comprende un módulo de seguridad interno y un módulo de seguridad cambiable. La señal del programa se codifica con una clave y la clave misma se cifra dos veces y se multiplexa con la señal de programa codificada. El decodificador hace un primer cifrado cuando el segundo número de serie secreto almacenado dentro del decodificador. La clave parcialmente decifrada se decifra aún más en el módulo de seguridad cambiable usando el primer número de serie almacenado dentro del módulo.A decoder for decoding satellite transmissions comprises an internal security module and a changeable security module. The program signal is encoded with a key and the key itself is encrypted twice and multiplexed with the encoded program signal. The decoder does a first encryption when the second secret serial number stored inside the decoder. The partially decrypted key is further decrypted in the changeable security module using the first serial number stored inside the module.
MX9201397A1992-03-271992-03-27
INDEPENDENT EXTERNAL SECURITY MODULE FOR A DIGITALLY GRADUABLE TELEVISION SIGNAL DECODER.
MX9201397A
(en)