To provide a highly safe and chargeable broadcasting service which does not oppress the broadcast band by distributing a large quantity of individual controlled information even if a number of subscribers increases and prevents illegal watching and listening.

A plurality of receivers for receiving contents information ciphered for broadcasting distribution decode contents informations to be decoded respectively, by using a decoding control information including an information specific to the respective receiver which is necessary to decode the contents information. The receiver receives an individual control information by every receiver to update partly or entirely the stored decoding control information through interactive communication, and it updates the stored decoding control information and further receives a key information necessary for decoding a contents information which is distributed by broadcasting and is independent of the receiver, and then it decodes the contents information distributed by broadcasting, on the basis of the key information and decoding control information.