Content Scrambling System

Content Scramble System (CSS) is a Digital Rights Management (DRM) scheme used on almost all commercially produced DVD-Video discs. It utilizes a relatively weak, proprietary 40-bit stream cipher algorithm. The system was introduced around 1996 and has subsequently been compromised.

The CSS key sets are licensed by the DVD Copy Control Association to manufacturers who incorporate them into products such as DVD movie releases, drives & players. Most DVD players are equipped with a CSS Decryption module. CSS key is a collective term for authentication key, disc keys, player keys, title keys, secured disk key set, and/or encrypted title keys.

Some of the keys are stored on the lead-in area of the disk, which is generally only read by compliant drives. Keys can be passed from a DVD drive to a descrambler over a PC bus using a secure handshake protocol.

It is an encryption system based on the proprietary 40-bit encryption stream cipher algorithm. Became real in the year 1996, now it is widely used in some of the DVD systems.

The Content Scramble System key set or the CSS key set, which contains the authentication key, disc key, player key, title key, second disk key set and the encrypted key, are legally outsourced with licences, to different manufactures, to use in their products like the DVD drives, DVD players and DVD movie releases.