The music industry's technical efforts to prevent CD piracy are "fundamentally misguided", according to a US technology expert.

Princeton University's John Halderman told New Scientist that CD copy protection measures will always be confounded by simple software upgrades.

Current copy protection wisdom is to issue CDs with dummy tables that interfere with the way computers read discs, thereby preventing them from working on computers.

If the CDs can't be read on computers then they cannot be copied. But Halderman told the magazine that this approach is flawed because the measures can easily be side stepped.

Makers of CD players and CD-Rom drives can make "relatively simple modifications" to bypass such measures, he said.

Halderman will detail his findings at a conference on digital copyright in Washington later this month.