Abstract: A scramble communication system comprises a station and a plurality of terminals connected to the station. The respective terminals are previously provided with specific scramble generation polynomials which are different from each other. In each terminal, its specific scramble generation polynomial is multiplexed with a transmission signal and the multiplex signal is transmitted to the station. In the station, the respective multiplex signals are received from the terminals and each the multiplex signal is divided into the specific scramble generation polynomial and the first transmission signal. The station scrambles a second transmission signal using the specific scramble generation polynomial obtained from the received multiplex signal. The scramble signal is transmitted from the station to all the terminals. Receiving the scramble signal from the station, each terminal descrambles the scramble signal by using its specific scramble generation polynomial.