Email this story to a friend Printable version

11th September 2002

CCL announces a breakthrough in audio watermarking

The record industry is losing money. At the last count, according to figures published by the International Federation of Phonographic Industries, the industry lost some $4.2 billion in 2001. And it is laying the blame firmly at the feet of pirates - people who burn CDs and sell them on or who place music on the internet for others to copy and distribute.

However, a highly advanced audio watermarking solution developed by Cambridge Consultants Ltd (CCL) and marketed by Activated Content Corporation (ACC) is providing the breakthrough that the industry needs. Essentially, an audio watermark is a signature, unique to a single copy or piece of music, which can be used to identify whether it has been pirated for CD or internet distribution and enable it to be traced back to its illegal and then legal owner.

"Every previous attempt to produce reliable watermarking has failed so far," says Simon Long, a Development Engineer with CCL who adds, "Up to now, watermarking has been beset by a number of seemingly insurmountable problems. These include making sure the audio watermark can't be heard and doesn't interfere with sound quality, ensuring that data capacity is large enough to carry the information needed to identify the music, and making the watermark recoverable even after the audio has been distorted or attacked by hackers bent on removing it. "We began by examining all the watermarks currently available and found that we could remove every one of them."

The challenge the CCL team set themselves was to create a watermark that couldn't be heard, had ample data storage capacity and was sufficiently robust to survive both the distortion introduced by typical distribution methods, such as MP3, and also to survive deliberate attempts to remove it by hackers. "We have succeeded in each of these areas," says Simon, adding: "In double blind testing, studio engineers were unable to hear the CCL audio watermark. The data rate is ample for identification purposes and we found that, once created, even the team at CCL who developed it could not remove the audio watermark. Furthermore, the watermark is extremely robust, and can still be recovered even after the audio has been distorted by, for example, the addition of hiss, wow and flutter or lossy compression algorithms such as MP3."

MP3 achieves its small file size by discarding parts of the audio signal that are deemed to be inaudible. As a result, many watermarks, as they are designed to be inaudible, are destroyed by MP3 compression. However, the CCL watermark has been designed to survive even in MP3 files, while remaining inaudible. "In essence, the audio watermark is protected by cryptographic principles. Each watermark has a key and if you don't know the key, you can't find and unlock the watermark," says Simon.

The watermarking technology was acquired from CCL by ACC, a US-based entertainment technology and services company. "For years, audio-based watermarking has been an attractive concept to the entertainment industry," said Stuart Rosove, President & CEO of Activated Content. "However, up until CCL's breakthrough, meaningful and practical commercial applications based on audio watermarking have not been technologically or economically viable."

ACC has already deployed high-end commercial solutions in mastering studios for major record labels in the US and is working with both labels and distribution companies worldwide on a variety of solutions that meet the various needs in the physical and electronic supply chain. "Broadband adoption has accentuated the need for solutions," adds Rosove, "and CCL's core technology is flexible enough to fit a host of different applications."

The CCL audio watermark can also be 'inserted' into the sound track of movies. For example, when promotional copies of films are distributed to cinemas, each can have its own personalised audio watermark and illegal copying can be tracked back to a particular cinema. Similarly films downloaded from the internet can also carry the watermark. "Effective audio watermarking represents a huge leap forward in combating piracy and CCL's audio watermarking technology represents the most advanced industry development in detecting the source of that piracy," concludes Simon.

For further information: