Watermark Standardization for DVD Copy Protection / Galaxy

On February 17, IBM, NEC, Pioneer, Hitachi, and Sony announced the formation of the "Galaxy" group to merge watermarking proposals for DVD copy protection, and on March 2 they submitted a unified proposal on video watermarking to the DVD Watermark Review Panel (WaRP). IBM's Tokyo Research Laboratory technology was selected as a core technology of the Galaxy group's proposal.

Background story of DVD copy protection

A DVD is a 4.7-gigabyte removable storage medium, and can accommodate two and a half hours of MPEG-2 encoded motion picture data. Hollywood expects that DVD will expand the home video market on account of its clear visual quality, just as CD audio spurred a remarkable growth in recorded music sales from 1988 to 1995. But they are also afraid that the prevalence of casual piracy may destroy the potential DVD market, since MP3 and the Internet are generating casual CD audio piracy and harming the recorded music market. (See background story on the music recording industry.) In 1996, the Motion Picture Association of America (MPAA), the Recording Industry Association of America (RIAA), consumer electronics manufacturers, and information technology companies formed the DVD Copy Protection Technical Working Group (CPTWG) to protect the new business opportunity in the DVD home video market from casual piracy. The DVD CPTWG began by launching an encryption approach called Content Scrambling System (CSS) in 1997. However, no encryption approach can prevent illegal copying through the analog output of a DVD player or stop circulation of unauthorized copies from person to person. Thus, CSS is not sufficient for protection against casual piracy.

IBM was the first proposer of copy and playback control by watermarking

Watermarks survive digital-analog conversion. In September 1996, IBM's Tokyo Research Laboratory (TRL) first proposed the use of watermarking technology for DVD copy protection at the DVD CPTWG, and showed that the TRL technology can detect embedded watermarks in both uncompressed and MPEG-2-compressed domains. This led to the development of a new framework in which DVD recording and playing devices automatically prevent unauthorized recording and playback of unauthorized copies by means of Copy Control Information (CCI) detected in digital video content. The new framework contains direct and aggressive measures to promote copy protection, but does not violate the privacy of consumers, unlike the conventional digital watermark framework, which was based on a "monitoring" and "tracking" approach whereby a system is assumed to embed a consumer's personal information invisibly in digital content for tracking purposes.

Data Hiding Sub-Group (DHSG) formed under DVD CPTWG

The new framework, which controls recording and playback by means of watermarks, requires the standardization of watermarking for effective implementation in consumer DVD devices. In May 1997 the Data Hiding Sub-Group (DHSG) was formed under the DVD CPTWG, and issued a Call for Proposals (CFP). The CFP defined a set of requirements, ranked as either essential or desirable. The essential requirements are as follows:

Call for Proposals issued by the DHSG in July 1997

• Transparency
• Low-cost digital detection
• Digital detection domain: The digital detection can be done in the source data (uncompressed digital video), MPEG-2 compressed elementary data, a multiplexed stream (program/transport), and/or logical sector data.
• Generational copy control for one copy
• Low false positive detection rate: no error lasting 10 seconds in 400 hours of operation.
  (Consumer electronics manufacturers now claim no error in "316,890 years" instead of no error in "400 hours.")
• Reliable detection
• Ability of watermark to survive normal video processing in consumer use.
• Licensable under reasonable terms
• No restrictions on export/import
• Technical maturity
• Data payload; three states (Never copy, No More Copying, and Copy Once) and an additional 2 bits for APS at a minimum.
  (the DVD CPTWG agrees to 8 bits of data payload)
• Minimum impact on content preparation
• Data Rate: at least 11.08 Mb/s

Eleven Proposals Reduced to Two in February 1999

The eleven proposals submitted in response to the CFP were subjected to the visual and survivability tests using common sample clips, in October 1997 and February 1998, respectively. In May 1998 the DHSG issued an interim report entitled "Results of Phases I and II" and IBM's proposal had the best survivability in the DHSG test. This report led the merging of the original eleven watermarking proposals into three by July 1998: an IBM-NEC proposal, a Pioneer-Hitachi-Sony proposal, and a Macrovision-Digimarc-Philips proposal. The watermarking technology of IBM's Tokyo Research Laboratory was adapted as the core of the IBM-NEC proposal. Consumer electronics companies such as Pioneer, Hitachi, and Sony have a strong interest in the transparency of watermarking. Beginning at the end of 1998, the IBM-NEC group and the Pioneer-Hitachi-Sony group held a sequence of meetings to evaluate the proposals technically. As a result, Pioneer, Hitachi, and Sony admitted that the IBM-NEC watermarking technology offers an acceptable level of transparency by allowing automatic visual control of the embedding processor. Thus, in February 1999, IBM, NEC, Pioneer, Hitachi, and Sony announced the Galaxy team for standardization of watermarking for DVD copy protection.

Final test in August 1999

The final test to choose one standard technique for DVD copyright protection, conducted by WaRP (Watermark Review Panel), started in Burbank, USA, at the beginning of August 1999. The test evaluated the competing proposals of the Galaxy group (IBM, NEC, Pioneer, Hitachi, and Sony) and the Millennium group (Macrovision, Digimarc, and Philips), and continued for more than one month. Both groups' techniques were evaluated with respect to various qualities, such as transparency, reliability, and survivability. Although the result has not yet been announced by WaRP, Galaxy achieved very successful results in every test and we strongly believe that victory will be ours.