More on the new digital copy protection scheme. Here we go again. "DVD players with 1394 interfaces currently are illegal".....
techweb.cmp.com
Posted: 9:00 p.m. EST, 2/19/98
Proposal addresses copy protection of digital data
By Craig Matsumoto
SAN JOSE, Calif. -- A five-company coalition
submitted a proposal to an industry group on
Wednesday that addresses the copyright
protection of video and audio in digital format.
Based on input from the film and recording
industries, the proposal appears to be the
frontrunner as a standard for digital copyright
protection, which many view as a requirement for
the deployment of digital broadcast TV in the
United States.
The proposal is the latest in a long string of
compromises and collaborations by the five
companies--Hitachi Ltd., Intel Corp., Matsushita
Electric Corp., Sony Electronics and Toshiba
Corp. The five had initially developed separate
proposals for copy protection. Their work was
coalesced into two separate proposals, and
eventually merged into this week's proposal, with
studios executives offering suggestions along the
way.
The film studio representatives "are always asking
for something that's more robust," while electronics
and computer companies press for a low-cost,
easy-to-implement solution, said Brendan Traw, a
staff systems architect with Intel Corp. (Santa
Clara, Calif.).
Digital copyright protection has been a critical
hurdle to the mass implementation of DVD players
and digital television. The film and recording
industries have been afraid that the pirating of
digital media--which can still be viewed in perfect
condition through multiple generations of
copying--will run rampant once consumers have
DVDs and digital TVs in hand. In fact, legal
requirements state that a DVD player with a 1394
interface can't even be manufactured without
compliance with an industry-wide digital-protection
scheme. This factor has drawn urgent attention
from consumer electronics firms who want to see
DVDs connected to digital TVs in households as
soon as possible. More importantly, the copyright
question has made Hollywood studios reticent to
release their content digitally.
The five-company proposal has been developed
for the IEEE 1394 serial interface, which the
companies consider the de facto digital interface
for consumer products. Even so, the proposal is
intended to be a broader solution. "Hopefully we
ended up with a system that could be used on
other interfaces," said Scott Smyers, director of
advanced digital interface technologies for Sony
Research Laboratories and chairman of the Digital
Transmission Discussion Group (DTDG), an ad
hoc group formed within the Copy Protection
Technical Working Group (CPTWG). DTDG
presented the proposal in Burbank, Calif., to
CPTWG, a coalition of media, electronics and
computer firms. The proposal was announced in a
keynote address at the Intel Developer Forum on
Thursday. Other proposals may be in the works by
other parties, including one from videoconferencing
pioneer PictureTel Corp.
The DTDG proposal uses four layers of
information to permit the transmission of a digital
signal. First, the content is labeled to allow either
zero copies, a single copy, or unlimited copying.
Second, the transmitting and receiving devices,
such as a DVD player or a digital TV, for example,
then verify one another's compliance with the
copyright standard. Third, the data itself is
transmitted in encrypted form, using standard
public-key techniques. Fourth, a "renewal" layer of
protection is included to thwart hackers from
circumventing the system. If a device is "hacked,"
the digital keys or certificates are sabotaged or
erased, which would cause the device to fail the
verification step.
The "renewal" step was among the suggestions
made by film studios during their review of the
existing proposals in December. The five-company
coalition responded by creating renewal protection;
representatives of the five companies were
unaware of any response from PictureTel or other
groups to the renewal requirement.
For the device-verification step (the second step),
specific authentication methods will vary depending
on the type of content. Items flagged as never to be
copied, for example, would use a full authentication
technique that uses the Digital Signal Standard and
Diffie-Hellman public-key techniques, based on
elliptic curve algorithms. One-copy content would
use a simpler challenge-and-response protocol. A
random number will initiate the verification step, so
that digital eavesdroppers can't crack the scheme
just by witnessing one verification attempt.
Encryption for the third step--during
transmission--is yet to be decided. The proposal's
authors are considering two methods: the M6
cipher algorithm devised by Hitachi, and a modified
version of the Blowfish cipher. "We tried as much
as possible to rely on well-known cryptographic
techniques," Intel's Traw said.
In large part, the proposal relies on the use of
digital certificates--a kind of unique ID badge for
electronic commerce. Verisign Inc., which makes a
business of being a "certificate authority," acts as a
third party to create and verify certificates for
online transactions.
The copy protection proposal probably will
establish its own third-party certificate authority,
members said, because studios would prefer that
method. Details for creating such an entity haven't
been worked out, however, and it's not known
who would run or own the authority. In any event,
the certificate authority would be given
responsibility for creating unique certificates for
every device that's compliant with the scheme.
The five companies will continue to work on their
proposal while the studios mull it over. Once
approved by the studios, a digital-protection
scheme could be implemented fairly quickly, the
companies said. A 16-bit microprocessor
embedded in consumer devices would probably be
sufficient, and could be developed in about six
months, said Hisashi Yamada, chief technology
fellow with Toshiba's storage business group.
All necessary intellectual property, as well as
design specifications, would be licensed by
developers from the certificate authority.
While no official deadline has been set for settling
on a digital-protection standard, the industries
involved hope to complete something this year in
time for the rollout of digital TV broadcasts in the
United States. |
