Patent ID: 8031870

Claim:
A conditional access system for a transmitter in a single frequency network for terrestrial and satellite digital broadcasting, the conditional access system comprising: a main broadcasting system configured to transmit encoded signals including a data stream and a main broadcasting system transmitter identification information (TII) value through a main broadcasting network; a repeating system configured to: amplify and transmit the encoded signals of the main broadcasting network, or modulate and amplify a stream input by the main broadcasting system through a private line, allocate a repeating system TII value to be different from the main broadcasting system TII value, and repeat the broadcasting signals, including the encoded signals of the main broadcasting network, through a repeating network, wherein the repeating system extracts the main broadcasting system TII value and inserts the repeating system TII value in the broadcasting signals when repeating the broadcasting signals; a subscriber station configured to decode the encoded signals of the main broadcasting network included in the broadcasting signals received through the main broadcasting network or the repeating network, transmitter identification information (TII), and an encoding key; and a decoding key provider configured to authenticate a user and transmit a decoding key to a charged subscriber station through a mobile communication network, wherein: the charged subscriber station is in the repeating network coverage, and the charged subscriber station is configured to store the decoding key transmitted from the decoding key provider and decode the broadcasting signals using the decoding key corresponding to the repeating system TII value.