Sony ISP in Japan, So-net, is working with JapanWave to provide protected, downloadable videos that stop working after a set period of time.The most common approach to protecting Internet-delivered music and videos is to stream them. The content distributor believes this will stop their content being permanently saved, which is not the case, as software has existed for a long time to store the streamed content to the local computer. The main problem with streaming is that viewing quality if dependant on the speed of its delivery – this doesn’t occur when the video is downloaded.JapanWave‘s approach is to fragment the downloaded video file and distribute those sections are around numerous directories on the receiving computer. The JapanWave player then reassembles these when the video is played back while checking to see if the video is past its “view by” date.As is common knowledge, all DRM’s systems are crackable and not surprisingly, the details of how Japanware protects the content aren’t given, but it sounds like a simple solution that will not detract from the viewers experience and should put off most casual hackers.