DVD copy protection

What is Content Protection for Recordable Media (CPRM)?

CPRM is a mechanism tied to recording media. Only some DVD recorders support it, but not many DVD players. Each blank recordable DVD has a unique 64-bit media ID etched in the BCA. When the protected content is recorded onto the disc, it can be encrypted with a 56-bit C2 (Cryptomeria) cipher derived from the media ID. In the play process, the ID is read from the BCA and used to generate the decryption key content in the disc. If the content on the disc is to be copied to other media, the ID will be absent or wrong, and the data cannot be decrypted.


What is Digital Copy Protection System (DCPS)?

In order to provide digital connection between components not allowed perfect digital copies, five digital copyright protection systems were brought up the CEA. DTCP (digital transmission content protection) is the first one, which focuses on IEEE 1394/FireWire but can be applied to other agreement yet. The draft proposal (called 5C, for the five companies that developed it) was made by Intel, SONY, Toshiba, Hitachi and Matsushita in February 1998. SONY released a DTCP chip in 1999.