Digital Audio Watermark Watch

In the perfect digital future, audiophiles would be able to drink from the purest of high-resolution audio datastreams with no worry that someone upstream had polluted the current. But in the real world, content providers and hardware manufacturers increasingly conspire to dirty the flow a little and limit unauthorized consumption by controlling the technology needed to filter out their toxic additives.

One of the more controversial additives, "watermarking," is a process whereby data that defines permissions for a digital music track is mixed in with the music. Digital audio playback software can then be programmed to detect the watermark and obey the permissions set by the content provider. However, audiophiles worry that any signal added to the digital audio stream, no matter how slight or cleverly concealed, will degrade the resultant sound (see Barry Willis' report).

But the drive to control the datastream continues unabated. Last week Verance and Sanyo announced that they have reached two long-term watermarking agreements. Under the terms of the first agreement, Sanyo says, it has licensed the Verance watermarking technology for SDMI Phase 1 applications. The second is a three-year royalty-bearing OEM Agreement that Sanyo says provides the company with optimized Verance software for watermark detectors to be used in Sanyo's SDMI compliant products.

Sanyo's Tatsuo Tanaka says that his company chose Verance copy protection technologies because of "Verance's position as the industry standard for SDMI Phase 1 and DVD-Audio." Under the OEM Agreement, Sanyo says, it will be able to focus on the development of products, with Verance providing the software to drive SDMI compliance.

Verance's Geoff Anderson adds that "it has become increasingly evident that electronics manufacturers and software vendors of SDMI compliant products require optimized watermark detection software from Verance to meet their time-to-market, processing, and consumer satisfaction demands, and Sanyo is leading the charge."

Also last week, Liquid Audio announced that has received a patent (#6,209,094) covering a technique for embedding watermark data in an audio signal that the company states is robust and cannot be removed without destroying the music. LA also claims that their watermark is "imperceptible and cannot be heard by the music listener."

The watermark technique, invented by LA engineers in 1998, is part of the company's four-part Digital Rights Management (DRM) system, intended to protect music distributed on the Internet. The DRM system includes encryption, watermarking, copy control and copyright management. LA's Leon Rishniw says that his company's patent "underscores Liquid Audio's commitment to provide innovative technology that addresses the current challenges of digital distribution."