SISTEMA DE SEGURANCA PARA TRANSMISSAO DE UM SINAL,DECODIFICADOR PARA RECEBER E DESCRUZAR UM SINAL,PROCESSO PARA TRANSMITIR UM SINAL FIRME,PROCESSO PARA DECODIFICAR UM SINAL,E MODULO DE SEGURANCA SUBSTITUIVEL

摘要

A decoder comprises a fixed security element (719), or replaceable security module, which includes a processor (713). The processor processes a once-encrypted key based on a key (SSN0) to generate a working key (KOM1) and processes scrambled program data based on the working key to generate decoder control information. The decoder is useable for descrambling scrambled signals.