I wonder, how difficult it would be to interface with the CableCard directly? I know that some people used to do something similar to that with satellite broadcasts where they let the satellite receiver act as the tuner, then had a dummy card the went into the decryption card's slot. This dummy card was connected to a computer, which in turn had a similar interface connecting it to the real card. The encrypted satellite feed could then be fed to the computer, to the real card for decryption, with the decrypted content being fed back to the computer (and usually back to the receiver through the dummy card).

Perhaps someone could try capturing the encrypted signal with a QAM tuner and feeding it to a CableCard. I assume the CableCard specifications are pretty available, so making a home brew interface to it should be pretty easy. The only real stopping point would be if there is some sort of authentication handshake required between the card and the reader that requires a special key.

And therein lies the rub...

I believe the cable cards will only output to "approved" devices, meaning it is locked down as all hell and has received a digital certificate from CableLabs. Our only hope is if someone figures out how to spoof the certificates.

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From the "CableCARDâ„¢ Copy Protection 2.0 Specification" that can be gotten here.


So you're right, until someone manages to grab certificates out of an authorized device, there isn't much hope of using a CableCard. Well, possibly someone could make a sniffer that sits between the host and the card to read the unencrypted MPEG-2 stream from the card as it's being controlled by the host. Still, that has DMCA violation written all over it.

It looks like the cable company can carry a revocation list for Card_ID and Host_ID. It also appears that if the EMI flag is set, the CableCard re-encrypts content before sending it back to the host, and the host can then use a negotiated key to decrypt the content. This is supposed to be useful for DVRs to store the video in an encrypted fashion.

It looks like you're right. The system seems pretty secure, so I'm guessing that it will take quite a bit of skill, and possibly shadowy activities to ever be useful within MythTV.

Systems with this card are now shipping from Velocity Micro.

Your thinking of an emulator. Only the encryption keys were feed to the PC to be routed through the smartcard which then gave back the decryption keys to pass back to the receiver to decrypt the video stream.

What you have to understand though is that satellite systems are basically one way communication. As long as you left the phone cord on your receiver unplugged there was no way for it to "phone home". You could hack the receiver / smartcard to your heart's content and they could never find you. The worst they could do is change something so it didn't work and then you had to update the emulator...it turned into a game of cat and mouse.

Cable on the other hand is 2 way communication. That means that if / when they figure out that you have modified (hacked) something they can "phone Home" over the cable feed and shut you down (or worse). The key difference is they know who you are.

With satellite the only purpose of running an emulator was to get something you weren't paying for. There was really no fair use purpose for it. What is proposed by adding a cablecard to a Myth setup is different in the fact that it would have substantial uses that fall under legal fair use. Unfortunately the DCMA made breaking encryption (even for fair use purposes) illegal and thanks to that it would not be a good idea to get caught "exercising your fair use rights" by hacking a cablecard into a Myth setup.

Martian

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