[mseebach2]

I think the distinction is between software and hardware DRM. DirecTV controls the entire hardware chain. This means they can do various proper encryption schemes (public/pre-shared key etc) that are actually near impossible to crack and make it really, really hard to obtain the key by making the key write-only in the crypto-chip.

In a pure software solution, you control the hardware, and any hiding of the key is subject to reverse engineering the software.

[georgemcbay]

There's also a distinction between access to the data stream vs the ability to make a duplicate of it.

For all of the success they've had in protecting DirecTV, if you've got a legitimate access card feeding HDMI data out, you can make a perfect digital copy of the video stream that has no copy protection whatsoever. So ultimately the DRM offers no protection for the media content companies (at least those that don't benefit from live performances like say sports games), though it does for the pipe provider who will surely get his monthly satellite fees.