by Paul Jay, CBC News Online

In the movies, faking a work of art is usually a matter of pulling the ol' switcharoo, Indiana-Jones style.

But in the real world art forgery is a problem, if only because it's becoming harder and harder to prove if something is fake. So curators are looking for methods to prevent theft and verify authenticity. At the University of Palermo they've come up with a rather interesting method: Taking a sonic fingerprint of the art.

According to Wired News, restorer Lorella Pellegrino and professor Pietro Cosentino got the idea when they spied a fake of a precious funeral urn called the Cratere dei Niobidi sitting in a cafe close to where the actual urn stood.

Working on the principle that every object emits a distinct vibration, each piece of art or cultural artifact is fitted with a network of sensors, then tapped with a small rubber hammer. Recorded vibrations form a unique sonic fingerprint capable of distinguishing even works made in pairs or series.

The two had already been using sonic tomography to test the urn and other precious objects for structural flaws. The method works for stone, wood and ceramic works.

The only problems with the technique? The cost of the machine is as much as 20,000 euros (or around $30,000 Cdn.), and the tests must be done every few years since the sonic signature of the object changes over time.