Cory Doctorow reports that he’s been told by DRM experts that line noise could not cause the copying restrictions that people are seeing with their Tivos. The restrictions are part of a Macrovision copy protection scheme, and Tivo claims that the protection is being tripped by data errors, as opposed to being enabled purposefully by broadcasters. I’ll be following this story as it develops.
September 15, 2005 at 2:26 pm
This actually isn’t the first time I’ve seen this come up erroneously, just the first time it turned into a big deal. Since it is illegal for broadcasters to restrict broadcast content it is extremely unlikely that this was anything other than an error. There is no point in broadcasters even having the ability to set the bits on their signal for anything other than PPV, OnDemand, etc.
My understanding from past conversations with folks at TiVo, and others, is that the system in question is controlled by simple bit flags in the VBI. And that it is possible that the pattern is accidentally produced by noise.
Now, maybe there is supposed to be a checksum run to confirm the bits, and maybe that is the real glitch in the TiVo software, but the paranoia around this is laughable.