Encryption method and apparatus in a conditional access system for digital broadcasting

摘要

An encryption method and apparatus in a conditional access system which interworks with a smart card to receive digital broadcasting are provided. A smart card interface acquires a random value rather than a fixed unique value, encrypts a key value with the random value, for communication with the smart card, and sends the encrypted key value and the random value to the smart card. Upon receipt of a response signal including descrambling information corresponding to the encrypted key value from the smart card, the smart card interface sends the descrambling information to a descrambler so that the descrambler can descramble scrambled broadcasting data. The random value can be the position information of a path with the highest energy, decided in a signal searcher of a terminal.