Consumer surveys by the International Data Corporation have revealed that between 10 percent and 20 percent of the population routinely engages in some type of unauthorized home video copying — whether using CD/DVD burners, videocassette recorders or file sharing services. This figure is set to grow with the increased proliferation and falling costs of DVD writers.
Cryptographically-based solutions such as conditional-access (CA) — offered by companies such as Canal+, Nagravision and NDS — protect the digital content on its way to the set-top box (STB) and, in the case of PVR devices, advanced CA protects the digital content while it resides on the hard drive. But as soon as the video leaves the STB, service providers and rights owners rely on analog copy protection (ACP) to guarantee their revenue streams by preventing unauthorized VHS and DVD copies being made that would effectively displace VHS and DVD rental, retail purchase and PPV revenues.
Solutions such as digital watermark-ing and ACP and are not based on cryptography. They are signal-processing-based technologies that embed the copy-protection measures within the content rather than the medium. Cryptography and signal-based technologies are not competitors, but they can effectively complement each other; once the content is rendered into analog form for viewing or listening, signal processing takes over, providing a further line of defense.
The most widely used recording device in the home today is the VCR, followed by DVD recorders and PVRs. ACP technology prevents copying by such devices by transmitting software commands from the broadcaster’s uplink center or headend to the subscriber’s set-top decoder. An integrated circuit inside the decoder receives the commands and adds the copy protection waveform to the analog video outputs. This copy protection technology is embedded in more than 80 million digital STBs, including more than 90 percent of those used in the UK, North America and Japan.
Even as we move into an era of digital rights management (DRM), ACP remains a key weapon. DRM systems are designed to deliver protected electronic content through a variety of media, which ultimately allow consumers a range of additional rights, within a managed environment. DRM technologies offered by companies such as IBM, Macrovision, Microsoft and Real Networks comprise various software-based electronic and security elements, such as content and rights encryption, tamper hardening, evidence and detection, secure registry, trust authentication, watermarking, and analog copy protection.
Copy protection is a critical element of most DRM technologies, but economical digital copying will arrive soon, so there is a great deal of work being done to develop the robust digital copy protection methods and other DRM solutions requested by rights holders and consumers.
Effective copy protection and DRM technologies allow intellectual property owners to receive proper compensation for their works, as well as give consumers certain rights regarding the management and movement of content. These rights would only be granted if the associated fees were levied fairly and paid easily.
A key requirement for the commercial future of digital TV is preventing unauthorized copying of content. The industry needs technology that increases direct revenues by allowing content owners and system operators to distribute their content many times over to more consumers (even those without PPV access), to control the rights attached to the content and to ensure that the rightful dues are retrieved.
Unless there is an implementation of broadly-adopted technology-based copy protection and DRM solutions, content holders will be reluctant to release premium digital content through the Internet, which is essential for the growth of broadband and consumer electronics sales.
The DVB and TV-Anytime are just two standards bodies developing specifications for content protection systems within digital broadcasting, consumer electronics and the emerging in-home digital networks. Many solutions have been submitted to these bodies in line with the aim of producing solutions that are open, interop-erable, flexible and have industry consensus.
Achille Di Virgilio is technical support manager for Macrovision UK.