Disclosed are a conditional access transmission system and method, and a receiving terminal and method. The transmission system transmits scrambled broadcasting signals including a network identification code (NIC) in the digital broadcasting service. A repeating system repeats the broadcasting signals transmitted by the transmission system to a subscriber station. In this instance, the NIC of the repeating system is different from that of a main broadcasting network. A receiving terminal descrambles the scrambled broadcasting signals by using the NIC and a descrambling key. According to the present invention, the charged subscriber can receive broadcasting signals or TPEG messages in the repeating network.