Apple recently filed an updated patent application with the U.S. Patent and Trademark Office for a digital rights management system similar to Microsoft's Windows Genuine Advantage.

The patent application No. 20070288886, titled "Run-Time Code Injection To Perform Checks," describes a DRM system that permits an application developer to inject code into the application's runtime instruction stream, which would restrict execution of the application to specific hardware platforms.

The document goes on to explain the different phases of code injection. The first phase involves an application developer or a platform maker authorizing applications to run on a specific hardware platform. Later, code is injected to perform periodic checks to ensure that the application is running on an authorized platform. If the check fails, a part of the application's execution string is stopped and the application becomes unusable.

The periodic check would be transparent to the user, the patent application states. It's designed to be implemented on Apple's latest operating system, the Mac OS X, which is currently not copy-protected.

If it sounds familiar, that's because the DRM system described by Apple resembles WGA, Microsoft's anti-piracy system that validates the authenticity of the software maker's products.

Microsoft's system, however, has been under attack for flaws that have reportedly resulted in millions of Windows users mistakenly being reported to Microsoft as software pirates.

A student at Beijing University in September sued Microsoft, claiming that WGA collects information about his computer use and personal data without his authorization.

Then in October, Microsoft decided to drop WGA as a security feature from an updated version of Internet Explorer 7. Microsoft said this would help promote the browser to a broader audience.