Copy protection plan squeezes home users
By Junko Yoshida
EE Times
March 22, 2004 (12:31 PM EST)
DUBLIN, Ireland — The "Authorized Domain," a potentially troubling concept defining what a consumer can and cannot do with copyrighted content on the user's own electronic equipment, is quietly taking shape in a subgroup of the Digital Video Broadcast (DVB) Project. The scenario has equal and opposite potential for liberating the legal use of copyrighted material and for exerting an unprecedented level of prior restraint on personal property.
Under the DVB's Copy Protection/Copy Management (CPCM) scheme, the group plans to tightly embed "authorized usage" metadata in content and to transmit "usage state information" specifying, for example, whether the content can be copied, stored, displayed or redistributed to other CPCM-compliant devices within a household and, if so, how many.
The scheme would give Hollywood the technical means to extend its control deeper into the home, by sending invisible electronic signals to consumers' personal electronics equipment to restrict the use of content.
A lingering issue, still under discussion, is how to make networks, interfaces and varied consumer boxes understand and execute the usage state information (USI). The concept affects the processing power, software and user interfaces required in a system design.
In theory, USI can be handled in a system via smart cards, software, hardware or the Windows operating system, DVB participants say. Moreover, "Consumers won't pay extra" for making their devices DVB CPCM-compliant, said Paul Szucs, manager of the standards and engineering department at Sony International (Europe) GmbH's European Technology Center. "Consumers' experience with DVB CPCM devices must be just as good as, or even better than, [with] noncompliant devices," he said.
Although the work is far from complete, the cross-industry group that has been crafting DVB CPCM reported its progress on the Authorized Domain at the DVB World 2004 Conference here earlier this month. Content owners such as movie studios, in collaboration with broadcasters, consumer electronics companies and PC vendors, are developing the standard for storage and distribution of content within a home.
By defining the Authorized Domain as a set of CPCM-compliant devices that "are owned, rented or otherwise controlled by members of a single household," DVB CPCM provides controls to "copy" and "move" content within and across domain boundaries, according to the group.
Subgroup members insisted that the spec — the result of four years of arduous efforts toward consensus on a definition of the Authorized Domain — is designed to "enable, rather than prevent" the distribution of content based on the broadest range of business models. Almost 30 companies are participating in the DVB copy protection subgroup, including the BBC, BskyB, Disney, Intel, Micronas, Microsoft, Panasonic, Philips, Sony and Warner Bros.
Mapping the technical spec to fit consumers' social and private behavior at home, however, is a tricky business. The issue could prove controversial, depending on how the spec is implemented and how the rules are enforced.
"Our goal is to keep it simple, keep it cheap and keep it easy to implement," said subgroup chairman Chris Hibbert, vice president of media technology and standards at Walt Disney Television International. According to Hibbert, DVB CPCM is intended to be self-managing, with little or no intervention required by the user and no return path. "There is no requirement for owners of CPCM-compliant devices to register their devices. Quite the opposite; there is a requirement to preserve consumer privacy." He added, "We want to do this without depending on Big Brother."
Hibbert compared the Authorized Domain to "a modular personal video recorder." Typical PVR functions, such as "acquisition, storage, processing and viewing," are implemented in logically separate units in the Authorized Domain, he said.
With the threat of movie "Napsterization" no longer theoretical but real, the industries have every incentive to agree upon a technical guideline — and fast. "If we don't get this done before the end of 2004, de facto systems will take over," cautioned Sony's Szucs.
Still, some consumers may find the Authorized Domain a disturbing encroachment. Even Szucs acknowledged the concept cold be "potentially contentious."
Yet, "I'd estimate that 75 percent of consumers would never have a problem with it," said Mike Paxton, senior analyst for converging markets and technologies at In-Stat/MDR, who termed the scheme "fairly benign." The remaining 25 percent, he said, "might be inconvenienced if they're trying to burn a CD or copy a DVD."
But failing to reach a solution on copy protection issues could be even more damaging, Szucs and Hibbert of Disney Television argued. If incompatible systems were to proliferate, said Hibbert, content owners would start "cherry-picking their own 'trusted' system. Both manufactures and broadcasters [would then] need to deal with multiple incompatible [copy protection] systems — and lawyers will make a fortune."
Under that scenario, said Szucs, "it would become very difficult for consumers to get a variety of high-quality content legally, without having to buy all the proprietary solutions."
That is exactly Microsoft Corp.'s concern, said Mark Jeffrey, the company's program manager for European media standards and policy, based in Geneva. If de facto systems rule the market, "we'd have to start writing so many different interfaces for proprietary solutions — such as one for a Panasonic device, another for a Sony device, etc.," Jeffrey said.
Not the only one
The DVB Project is not the only place copy protection debates are taking place, nor is DVB CPCM the only spec necessary for protecting content (see table, page 1). An end-to-end copy protection scheme often requires various technology pieces, ranging from conditional access and digital rights management (DRM) to broadcast flags, scrambling, encryption and watermarking.
DVB CPCM does not touch those matters. It is "not conditional access, and it is not digital rights management," said Giles Godart-Brown, R&D program manager for British Sky Broadcasting and a chairman of the DVB Commercial Module responsible for copy protection.
Rather, according to the DVB, CPCM offers "a connection point" for various DRM and conditional-access schemes. DRM, Godart-Brown said, involves "the prevention of illegal distribution of content via the Web, and not directly its storage and distribution at home." Conditional access, meanwhile, controls access to content, not necessarily its storage and distribution. CPCM will communicate with both types of systems, where necessary, to enable additional controls, Godart-Brown said.
Within the DVB Copy Protection Technologies subgroup, participants are defining five abstract functional blocks, said Sony's Szucs. They are acquisition, the point where content enters a CPCM Authorized Domain; storage; processing; consumption; and redistribution, where content leaves the Authorized Domain, if allowed. The group is defining firm terminology and a concrete meaning for each block, he said, in order to establish a reference model.
"Work is ongoing on how these abstract functions can be mapped to logical and physical entities like devices, interfaces and networks," Szucs said.
Once the reference model is in place, the group must devise a system specification, including a scrambling method. Disney TV's Hibbert listed as big technical challenges "the security of communication between devices; the method of securing the content; and the means of securely binding the usage state information to the content."
In-Stat's Paxton described "the actual copy protection/copy management software" as "the toughest piece of technology" to create. Consumer electronics vendors, he said, have tried before to "place these unbreakable shells of software around digital content on CDs and DVDs" and have never really succeeded. The key challenge has been to keep the software from being hacked. "Once the copy protection systems have been undermined, it's simple for pirates to make unlimited copies of the music, videos or software," Paxton said.
One wrinkle in the Authorized Domain concept would occur when equipment changes hands. Hibbert acknowledged that divorce is a case when one or more devices could move from one Authorized Domain to another. The owners "will need to decide to which Authorized Domain that content — which is labeled as restricted to one [domain] only — will be assigned." Not all content, he added, "will be signaled as restricted to only one Authorized Domain; it depends on the associated distribution rights."
