抄録
The DVD content scramble system (CSS) has been developed for protection of copyrighted materials on DVDs from users' unauthorized copy. The system is based on the encryption technology developed by Matsushita. The technology has been agreed by engineers in the industries of consumer electronics, motion pictures, computers, etc. through discussion in the DVD Consortium. The CSS is to prevent "casual copy" by simply connecting AV signal cables or using a computer. For this purpose, the system has the following mechanisms.(1) Content scramble : Copyrighted material (MPEG compressed content) is scrambled using three layered encryption keys. Only DVD products with licensed technology can obtain and playback the copyrighted material.(2) Bus-authentication : DVD-ROM drive and MPEG decoder module mutually authenticate through PC bus. The descrambling key is further encrypted by a time-variable key. This mechanism prevents unauthorized copy of copyrighted material on PC bus and its playback.
