DRM Demystified

Microsoft’s Windows Media Rights Manager
Originally launched in 1999 as the "Digital Broadcast Manager," Windows Media Manager has evolved over the past nine years into a widely deployed industry standard used by Amazon, Wal-Mart, Napster, MovieLink, AOL, Yahoo!, and Rhapsody. There are literally thousands of licensees of the technology and a whole ecosystem of devices, phones, and portable media players that support the technology from the likes of Samsung, Phillips, Denon, Toshiba, Dell, Palm, RCA, HTC, and numerous others.

Often mistakenly referred to as "PlaysForSure DRM" or "Windows Media DRM," the Windows Media Rights Manager is a free technology that can be licensed from Microsoft and includes both content encryption and license-key generation components. WMRM supports a variety of business models and output protection schemas and is built into the Windows Media Player, which ships on every Windows PC sold in the world. For more information on Windows Media Rights Manager, see http://www.microsoft.com/windows/windowsmedia/forpros/drm/default.mspx.

Microsoft will make a new DRM technology, PlayReady for Silverlight, available to developers in 2008. Click here for an interview with Microsoft general managers Adam Berns and Jim Alkove about the new technology.

Widevine Cypher for Flash
In April, Widevine launched Cypher for Flash and demonstrated this product at NAB in Las Vegas. From Widevine’s website: "Widevine Cypher is a downloadable conditional access, digital rights management, and digital copy protection solution that secures linear broadcast, VOD, file downloads, progressive downloads, and streamed media." I recently spoke with the company about how this technology works and learned that Cypher uses a conventional DRM model of content encryption and license serving.

Previously encoded Flash content is encrypted using AES 128-bit encryption via a Widevine Cypher encryption server. The output FLV content is electronically scrambled and in this state is basically unusable. Content is then published to a Content Delivery Network or hosting environment and made available to consumers.

At the point where a user requests to view or listen to a piece of content managed by Widevine’s Cypher, users are required to install and run the Cypher client. The client then receives a license from Widevine’s License Server service to decrypt the content and securely passes it to the Flash client where it is played back on the user’s PC. The Cypher client continuously monitors the user’s playback environment and thwarts potential applications that attempt to copy or screen-capture streaming or downloaded SWF content.

For more information on Widevine Cypher, see http://www.widevine.com/pr/109_cypher_flash.html.

RealNetworks Helix Security
Originally touted as a solution to address a variety of file formats, RealNetworks’ Helix DRM actually mandated that content be encoded in Real’s proprietary RealMedia format. Back in 2003, I called Real to get pricing on this product and was told that the Helix DRM Packager SDK was $180,000 and the Helix DRM License Server SDK included a license of $40,000 per CPU and required a special plugin for the RealServer if content was to be streamed. On top of these fees, Real wanted approximately 12% of any top-line revenue from the use of the product.

Needless to say, this product never took hold in the marketplace and was abandoned by Real when it moved to the Windows Media Rights Manager DRM platform for their Rhapsody offering. Helix DRM is no longer available from Real and today Real only offers a Helix Security technology that is similar to URL hashing using tokens, which is commonly available from many of the industry’s CDNs.

For more information on Helix Security, see http://www.realnetworks.com/products/security/index.html.

DivX’s Open Video System
DivX has been operating the OVS platform, which includes a DRM component, for nearly six years now and provides the service as a turnkey platform hosted by DivX for its customers. The product is primarily in use in the adult video marketplace, where companies like Gamelink and HotMovies use the technology side-by-side with their Windows Media Rights Manager offerings.

DivX has done a great job of licensing their core DRM and codec technology to numerous different devices, portable media players, and DVD manufacturers to further support the playback of encrypted DivX content beyond the PC. However, they have not done a very good job of licensing the technology out to third parties, and to date there are no major media outlet licensees of the platform.

For more information on DivX Open Video System, see http://www.divx.com/company/partner/ovs.php.