There are various copy protection systems and programs to prevent illegal copying of DVD video and audio content. Here is the state of play :

Analogue Protection System (APS) involves the activation of circuitry in the DVD player by so-called "trigger bits". An integral part of the DVD format, the Macrovision Copy Protection is to date, the only such system in use.

Copy Generation Management System (CGMS) is a means of marking and identifying the permitted status of the material on the disc. This analogue system has a planned digital implementation.

Content Scrambling System (CSS) is a form of data encryption, developed under the auspices of the multi-industry Copy Protection Technical Working Group (CPTWG) and now administered by the DVD Copy Control Association.

Content Scrambling System 2 (CSS2) is focusing on DVD-Audio copy protection (Due to security concerns expressed by the recording industry, among others, as a result of the recent "hack" of the CSS video technology, the DVD CCA has withdraw the CSS2 technology from consideration for use with DVD Audio products. A substitute encryption system is under devlopment).

Digital Transmission Content Protection (DTCP), backed by Intel, Sony, Hitachi, Matsushita and Toshiba.

Content Protection System Architecture (CPSA). Establish overall system architecture for protected content. Proposed by the 4C group (Toshiba, MEI, IBM and Intel).

Content Protection for Prerecorded Media (CPPM). DVD-Audio copy protection scheme proposed by 4C.

Content Protection for Recordable Media (CPRM). Provides effective protection against unauthorized casual consumer copying of audio/video entertainment content. Proposed by 4C.

Content Protection Framework, a DVD-Audio copy protection scheme.

3DCD, a joint venture between Technicolor and Applied Holographics, which has developed a proprietary edge-to-edge holographic technology.

Secure Digital Music Interactive (SDMI), through which the music industry is promoting a secure copy protection system for its material.

Galaxy The group (Hitachi, IBM, NEC, Pioneer, Sony) proposed a video watermark technology for CSS.

Verance. An audio watermark for DVD-Audio and SDMI.

Copy Protection Technical Working Group (CPTWG) is a voluntary group chaired by IBM. It meets monthly in Los Angeles. Attendees include consumer electronics maker, the IT, movie and music Industries, CEMA, MPAA, RIAA, etc...

	Copy Protection situation

Items	Method	Technical Answers
Media Identification	Media recognition	1. Book Type in the Control Data zone 2. Wobble detection
Never Copy (CSS)	CSS Key protection	Embossed or pre-recorded (for DVD-R General)
Once Copy   (Revocation)	Serialization	NBCA for DVD-RW Under discussion for DVD-R General

	CSS KEY System

	NBCA Copy Protection