Preservation and improvement of television advertising in digital environment

摘要

A system for protecting commercials included in a digitally distributed and recorded video that minimizes user's inconveniences resulting from restrictions imposed on playback of the video. The video is encrypted at the distributor side and playback of the encrypted video at the user side is limited in such a way that fast forward and reverse playing is not performed, and a lower limit is imposed on skip forward and backward so that only parts of video whose playing time is greater than the time of typical commercial break can be skipped. This arrangement prevents a user from selectively skipping commercials without missing pieces of program itself and thus discourages skipping when the user wants to watch an entire program, but still enables quick browsing before watching the entire program as well as moving fast to any part of the program for watching that part again.