PURPOSE: To attain ciphering control of an optional channel such as an optional floor from other location such as a supervisor's room.

CONSTITUTION: A head end device 1 for television common viewing rebroadcast receives a video signal carrier from various signal sources or the like by a television receiver 2, converts the frequency and a mixer 3 mixes the frequency and the frequency is distributed to each floor by one trunk cable C1. A control signal from a ciphering central controller 4 is sent on the same trunk line cable C1 by a frequency different from the video signal carrier. A distributer 5 is arranged to a location corresponding to each floor of the trunk line cable and the signal is delivered to each room via a branch cable C2 and distributed to a television receiver 8 by a distributer 7 of each room. A ciphering control terminal equipment 6 comprising a trap filter or the like is installed to a branch point of the branch cable and a ciphering central controller 4 selects an optional channel of an optional floor and a specific channel of a specific floor is ciphered by inserting the trap filter of the ciphering control terminal equipment.