MusiCode and rival digital watermarking technology from Blue Spike Inc. are both candidates for selection as copy-protection technology by the 4Cs (IBM, Intel, Matsushita, and Toshiba). Privately-held Aris (Cambridge, Mass.), which had revenue of about $1 million in 1998, would receive a tremendous boost if MusiCode is chosen as the watermarking technology for DVD audio and other digital music players, such as those being designed by SDMI.

MusiCode, which includes inaudible copyright-protection data and provides proof of ownership, proof of copyright violation, and prevents unauthorized copying of digital music, would make a good fit for the 4Cs, said David E. Leibowitz, president and vice chairman of Aris. The technology requires little processing power and memory for the coding and decoding of audio files in real-time, and can be easily implemented on chips for DVD-audio and low-cost digital audio players, he said.

Leibowitz said he is looking forward to hearing the outcome of the 4Cs' decision, but said MusiCode will find other markets for if it is not chosen by the 4Cs.

Separately, Blue Spike outlined parts of its Giovanni watermarking technology this week. The technology is based on patents which combine a secure, cryptographic key and an embedded signaling process for any media content, including audio, video and images, said Scott Moskowitz, chief executive officer of Blue Spike.

Blue Spike separates digital watermarks into two parts, each with a different purpose and different requirements: one is for copy control to eliminate "casual piracy," and the other serves as a forensic watermark. By separating the watermarks, Blue Spike ensures the security of the forensic watermark, and enables the copy-control watermark to survive lots of manipulations, said Moskowitz. "Separation of watermarks is part of our patents."

Aris has stepped ahead of some of its competitors by reaching agreements with various companies to cultivate applications for MusiCode. These include NBC Sports; record label Platinum Entertainment; Musicmaker.com, an online music compilation service; Lucent Technologies; and N2K, which will incorporate MusiCode into its Music Boulevard and Online Music Library distribution systems. In addition, SESAC (Nashville, Tenn.), a performing rights organization, employs MusiCode to identify and track musical performances.

Aris said MusiCode meets the five critical requirements for watermarking technology: it is secure; low cost (it could be used in a $89 Walkman, the company said); inaudible; supports a sufficient data-rate; and is robust to distortion. It is based on a technique called statistical feature modulation, where digital audio features are measured and modulated so that audio carries the digital watermark. The watermark becomes an integral part of the audio and remains with it regardless of its medium or carrier — analog or digital radio, TV, cable, or satellite, whether on a CD, DVD, videotape or cassette, or delivered over a telephone or the Internet.

Aris said its watermark technology survives digital-to-analog conversion, data and dynamic compression, manipulation by a broadcast studio, or the addition of voice-overs and effects for radio and TV broadcasts. The embedded watermark data can't be removed from audio content without seriously affecting the fidelity of the original audio material, Aris said.

Eric Metois, a DSP engineer at Aris, said the Aris algorithm would require only about 8 Mips of processing power to handle real-time decoding and would not require special handling to embed the algorithm into a chip. Aris is experimenting with simple watermarking technology that would require less processing power and could be used in small, cheap devices, he said. To illustrate the "light" processing requirements of the technology, Metois demonstrated two decoders working in real-time on a 133-MHz Pentium laptop.

MusiCode can achieve data rates of up to 40 bits per second, after error correction, according to Aris.

Metois said chip vendors could easily implement Aris' watermarking technology once they have the Aris algorithm, a block diagram and a license for the technology. "In a block diagram, each one of the blocks are fairly common blocks and implementing them in a VLSI design would not require much special effort," Metois said.

The company is currently in discussions with several chip vendors interested in implementing the technology. Metois and Leibowitz declined to name the vendors.

Meanwhile, Blue Spike claimed its watermark technology is robust and tamperproof. Touching on its technology's processor requirements and its encoding and decoding speed, Moskowitz said, "Our end-to-end system will do all the watermarking and runs on a Windows or Mac. Speeds [for a 400-MHz processor] are better than real-time for encoding and 30 times real-time for decoding." It takes less than 20 seconds, worst case, for the technology to determine if a signal is from a legacy disc or has been tampered with, he said. The company plans to release its own spec and software this month. Will it find a place in low-cost consumer electronics players? "Inevitably, digital watermarking is an invaluable security technology," Moskowitz said.

Aside from its core MusiCode technology, Aris has developed a technology to protect its watermark against "collusion attacks" by music pirates. Such attacks occur when several people each acquire a digital copy of the same content (a song, for example), each of which contains a different watermark in the file. In a collusion attack, the different copies are merged, or "averaged," then divided in an attempt to weaken or remove the watermark.

Aris said many of its competitors use a different digital watermarking technique based on spread-spectrum technology, in which a watermark is injected into the spread throughout an audio file.

The watermark signal created by the spread-spectrum technique is soft and difficult to make inaudible, Aris said. Companies use different approaches to try to hide these watermarks, Metois said. And the decoding of spread-spectrum-based watermarks is very expensive, he said.

Larry Fast, a former keyboard player for Genesis, and a producer of electronic music under the name Synergy, embeds the Aris watermark in all of his recordings. Because many of his pieces are sampled in other albums, Fast said he needed a quick and accurate way to track that use. The Aris technology is inaudible and does not change the original content's sound, according to experts in the industry, called "golden ears," who Fast said he has asked to test the technology.

— With additional reporting by Junko Yoshida