How does DeCSS work, exactly?
DeCSS operates much as any other DVD player operates – it uses a player key to unscramble the scrambled contents of a DVD to make playable MPEG-2 video files. DeCSS uses a player key obtained from the Xing software-based DVD player for Windows. All versions of DeCSS currently in release are built around the Xing player key, which reportedly has been revoked at the time of this writing. If this is true, no newly-released DVDs can be descrambled with this player key; DeCSS will not work on these DVDs. The “keyless” algorithm developed by the LiViD group was never incorporated into DeCSS. This algorithm allows the real-time identification of an available player key from the data on a DVD disk. It is not truly keyless; the algorithm determines a valid player key at run-time.
