A patent issued to Microsoft Research in Dec. 2001 hints at how future operating systems (OSs) might protect copyrighted content. The patent describes a "digital rights management operating system" that restricts copying of digital data at every point during playback or use. Similar features built into Windows would make it much more attractive for publishers to deliver digital music, video, and books via PCs and would give Microsoft a major advantage over competing digital rights management (DRM) systems.

The requirement for a digital rights management operating system (DRMOS) arises because the PC can easily be made into a platform for the inexpensive mass-duplication of the content with little or no quality degradation. Microsoft has already begun to build DRM technologies into Windows to address this problem: Windows ME and XP include Secure Audio Path (SAP) technology, which protects audio data as it is processed by a sound card, making it harder for miscreants to bypass copy protection on Windows Media Format (WMF) audio files. However, a DRMOS could provide complete end-to-end protection for any type of data, from the initial loading of the OS, through execution of any programs, and even into temporary data storage in memory, rather than just protecting the processing path for audio as SAP does. This could bring an end to "ripping" utilities that copy digital content and could reduce the appeal of third-party DRM systems that are unable to protect digital data at all points in the system.

For the Microsoft DRMOS patent, see http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=/netahtml/srchnum.htm&r=1&f=G&l=50&s1='6,330,670'.WKU.&OS=PN/6,330,670&RS=PN/6,330,670.

For more information on Microsoft’s Secure Audio Path technology, see "Windows XP Gives New Push to Windows Media Format" on page 10 of the July 2001 Update.

Microsoft’s Research cryptography site is at research.microsoft.com/crypto.