The U.S. Patent and Trademark Office issued the patent Tuesday.
Analysts said the significance of the patent was unclear, given the complexities of intellectual property law. But some downplayed the patent's importance, noting that many of the claims appear related to technology from rival InterTrust Technologies--a company that has sued Microsoft for patent infringement over its so-called digital rights management software.
"I'm assuming it's...posturing," Jupiter Media Metrix analyst Aram Sinnreich said about the patent. "There are a lot of references to InterTrust technology in the documentation."
Microsoft could not immediately be reached for comment.
Microsoft has bet heavily on digital rights management in its battle for dominance in digital media, a market the company sees as crucial to extending its Windows operating system from PCs to servers.
An InterTrust spokesman Thursday said there appears to be nothing new in Microsoft's patent, but it raised concerns about the software company's growing sway over a key new digital technology.
"While new, this patent is relatively limited and relatively late," InterTrust spokesman Ed Fish said. "Companies need to be careful about who they trust as a gatekeeper...If Microsoft owns the locks to Viacom content, it's like Sumner Redstone giving Bill Gates his front door key."