| 摘要 |
PROBLEM TO BE SOLVED: To sufficiently protect a copyright even in the device level of a reproducing means such as a monitor and a loud speaker or a device driver level. SOLUTION: When encoded picture data 35 with a user ID is received from a data supply source device 30, a CPU/chip set/memory 51 transfers a picture to a picture output device 54, analyzed watermark information, compares the user ID obtained from watermark information with the user ID which is previously set in the device level such as a data reproducing device 50, the monitor 59 or the loudspeaker 58, performs decoding with the user ID as a key when a condition required for reproduction is satisfied and, then, displays a decoded picture. Unless the condition required for reproduction is satisfied, display and a voice output are not performed. |
