Researchers at the University of Maryland have developed new digital rights management technology that they claim will help organisations better protect multimedia content from unauthorised copying and distribution.

The technology works by embedding a unique ID or "fingerprint" on individual copies of multimedia content. The tool features special codes designed to withstand so-called collusion attacks that occur when multiple users conspire to electronically steal and distribute copyrighted material, said Ray Liu, professor of electrical and computer engineering at the University of Maryland's Clark School.

Tighter controls

In such attacks, copyrighted material, such as an unreleased movie, might be stolen and pieced together from multiple copies in an attempt to dilute or erase the original digital identities associated with each copy, said Liu.

"If you can find 100 people to collude together, you can reduce the fingerprint by 100 times, and nobody will be able to identify" the source of a particular leak or copyright infringement, he said.

The digital fingerprint code developed by the University of Maryland is designed specifically to resist such attempts at dilution and allows content owners to trace sources better than with other digital rights management technologies, said researcher Min Wu, an assistant professor at the school.

"A lot of the existing technology cannot really reduce the effects of collusion," she said. "If multiple users generate one version, we can tell you all those who contributed to it."

Digital fingerprints

The digital fingerprints can be applied to images, video, audio and documents such as digital maps, according to the researchers. It can even be used to protect live multicasts such as pay-per-view events.

Several companies – including Sony BMG – have already expressed interest in the technology, Liu said.

"Sony is very interested in this and has donated over $120,000" toward equipment for a multimedia lab, Liu said. Others that have expressed interest include Hollywood studios and the US Department of Defense, he said.