Why can't the
content in DVD be duplicated in the usual ways?
Generally, DVD movies adopt a copy-protection
technology ,we call it CSS. Digital copy protection is provided by the
Content Scrambling System (CSS), which is used to scramble the video data
on a DVD-Video disc. Each video title set (VTS) can be selectively
scrambled using a unique key. Each unique title is assigned one Disc Key
and up to 99 Title Keys (one per VTS), which are stored on the disc in
encrypted form. In the decoder, the original keys are obtained by
decryption and used to descramble the data . For DVD-ROM drives, the
MPEG-2 decoder challenges the drive and receives the necessary keys for
decryption.
This ensures that only approved hardware/software can be used. The keys
used should be unique for every disc title and are encrypted by the CSS
Licensing Authority and, usually, the scrambling is carried out during
glass mastering. Security is vital and the keys used plus the encryption
algorithms must be kept secret. Only those companies involved in designing
hardware and software for CSS encoding and/or decoding need information on
the algorithms and systems used.
With the powerful technology, we have managed to decode the copy
protection. You can clone your DVDs with
DVD-CLONER comfortably. |
