Patent ID: 8255679

Claim:
A content playback apparatus which downloads and playbacks content data comprising: a receiving unit being adapted to download said content data which is encoded and key information for decoding said content data; a storage unit being adapted to store said downloaded content data; a decoding unit being adapted to decode an encryption of said stored content data by using said key information; an input unit being adapted to receive a playing back instruction; and a control unit being adapted to control said receiving unit and said decoding unit; wherein controlling states of said control unit includes, a first state that said key information is obtained after all downloads of said content data have been completed and said encryption of said content data is decoded to enable a playback; and a second state that said key information is received before a all downloads of said content data have been completed, and said encryption of said content data is decoded to enable a playback before all downloads of said content data have been completed, if said playback instruction is received from said input unit during the downloading of said content data.