Abstract: An AV system that permits only a single copy of an AV content without encryption and prevents the copy from being further duplicated in order to protect the copyright is provided. The hard disk of a home server is divided into a secure system region and a non-secure user region. A PC searches for the home server to establish a connection for authentication. The PC includes a ripping unit and a reproducing unit. The network type audio apparatus also includes a reproducing unit and is authenticated. The ripping unit rips music data from a music CD after the authentication and duplicates the data in the system region. The reproducing unit reads out music data from the system region after the authentication and reproduces the music data by a streaming method.