Film and TV studios require technical mechanisms to reduce the ways in which people can use that content, such as preventing people from making copies. This technical mechanism is generally called "DRM" for "digital rights management." Browsers must implement DRM in a way that makes the content owners comfortable. Otherwise they won?t allow their content to be viewed through that browser.
The industry is on the cusp of a new mechanism for deploying DRM. Until now, browsers have enabled DRM indirectly via Adobe's Flash and Microsoft's Silverlight products. The new version of DRM uses the acronyms "EME" and "CDM."
Mozilla think this new implementation contains the same flaws as the old system, as the content providers require that a key part of the system be closed source.
Google, Microsoft and Apple have already implemented the new system in their browsers.
Firefox will wrap Adobe's CDM into an open-source sandbox sealed off from a user?s hard drive and network. The sandbox will only allow the CDM to communicate enough externally to show the content. It will not allow device fingerprinting.
"Instead, the CDM asks the sandbox to supply a per-device unique identifier," Gal wrote. "This sandbox-generated unique identifier allows the CDM to bind content to a single device as the content industry insists on, but it does so without revealing additional information about the user or the user?s device."
To prevent tracking across a number of websites, Firefox will change the unique identifier presented to each site, making "it more difficult to track users across sites with this identifier," Gal wrote.
Mozilla will distribute its open-source sandbox, but the CDM will have to be downloaded from Adobe, Gal wrote.