BBC's plan to kick free/open source out of UK TV devices

My latest Guardian column, "The BBC's digital rights plans will wreak havoc on open source software," describes how the BBC's plan to add DRM to its high-def broadcasts will exclude free/open source software from use in digital television applications, slowing down innovation, raising costs, and harming the public interest. The BBC's regulator, Ofcom, will soon hold a second consultation on the Beeb's plan to add DRM to high-def broadcasts, and I'm urging them to get the BBC to answer for this consequence of the DRM plan. The entire DTLA system relies on the keys necessary to authenticate devices and unscramble video being kept secret, and on the rules governing the use of keys being inviolable. To that end, the DTLA "Compliance and Robustness Agreement" (presented as "Annex C" to the DTLA agreement) has a number of requirements aimed at ensuring that every DTLA-approved device is armoured against user modification. Keys must be hidden. Steps must be taken to ensure that the code running on the device isn't modified. Failure to take adequate protection against user modification will result in DTLA approval being withheld or revoked. This is where the conflict with free/open source software arises.
Free/open source software, such as the GNU/Linux operating system that runs many set-top boxes, is created cooperatively among many programmers (thousands, in some cases). Unlike proprietary software, such as the Windows operating system or the iPhone's operating system, free software authors publish their code and allow any other programmer to examine it, make improvements to it, and publish those improvements. This has proven to be a powerful means of quickly building profitable new businesses and devices, from the TomTomGo GPSes to Google's Android phones to the Humax Freeview box you can buy tonight at Argos for around £130.
Because it can be adapted by anyone, free software is an incredible source of innovative new ideas. Because it can be used without charge, it has allowed unparalleled competition, dramatically lowering the cost of entering electronics markets. In short, free software is good for business, it's good for the public, it's good for progress, and it's good for competition.
But free software is bad for DTLA compliance.