The new authentication system, announced Tuesday and due to arrive by midyear, will still allow people with pirated copies of Windows to obtain security fixes, but their options will be limited. The system allows Microsoft to use one of its sharpest weapons--access to security patches that can prevent viruses, worms and other crippling attacks--to thwart a costly and meddlesome piracy problem.
But some security experts said the crackdown also could increase Internet security problems in general, if there is a spike in computers open to attack, which then could be used to attack others.
David Lazar, a director of the effort, said Microsoft would monitor that potential problem closely. But the company actually considers its authentication requirement one possible way to boost Internet security because pirated copies of Windows could contain viruses or other security threats, he said.
Over the next few months, the software behemoth will begin to more broadly adopt the program, called Windows Genuine Advantage, that urges users to provide proof their Windows copy is authentic before receiving some software updates.
By mid-2005, the program will become mandatory for Windows users to get virtually all updates, including security fixes available through the company's Windows Update Web site. But users who have pirated copies of Windows will be able to continue to get security fixes if they sign up to automatically receive security updates.
Russ Cooper, a senior scientist with Cybertrust Inc., said he expected Microsoft to eventually cut off security updates for pirated copies.
"The reality is that shareholders of Microsoft would like to see them get all the money they are owed,'' Cooper said.