Central Research Laboratories (CRL) (W)

CRL's Audio Watermarking is a technique for embedding data codes within audio in such a way that the perceived quality of the audio is undisturbed. In a music application, it can be used for persistent identification in the following ways:

• An ID code can be added during production transaction.

• Tracking codes identifying the purchaser can be added when the music is sold or played.

• Access control codes can be added that enable a user to play or copy the music; this can also be used to prevent a user from playing or copying music.

CRL's Audio Watermarking technology has the benefits of audibility, high payload, and robustness. The robustness features include:

• Analog-to-digital and digital-to-analog conversion

• Compression (e.g., MP3, AAC)

• Radio and TV broadcast (AM, FM)

More information can be found at www.crl.co.uk.