4 ms·
At least for HDCP, that's exactly how it works. From the HDCP 2.2 spec [1]: > Device Key Set. An HDCP Receiver has a Device Key Set, which consists of its corr
by kbolino 2y ago
At least for HDCP, that's exactly how it works. From the HDCP 2.2 spec [1]:
> Device Key Set. An HDCP Receiver has a Device Key Set, which consists of its corresponding Device Secret Keys along with the associated Public Key Certificate.
> Public Key Certificate. Each HDCP Receiver is issued a Public Key Certificate signed by DCP LLC, and contains the Receiver ID and RSA public key corresponding to the HDCP Receiver.
> The top-level HDCP Transmitter checks to see if the Receiver ID of
the connected device is found in the revocation list.
[1]: https://www.digital-cp.com/sites/default/files/specifications/HDCP%20Interface%20Independent%20Adaptation%20Specification%20Rev2_2_FINAL.pdf https://www.digital-cp.com/sites/default/files/specification...
- _yb2s 2y agoThanks, that clarifies my confusion about how this could be realistically implemented. I couldn't see a practical way to verify every device on every connection via a central authority without massive scaling and reliability issues, but maintaining a small revocation list that can be cached everywhere media is distributed from seems quite practical.
- mike_hearn 2y agoFWIW, efficient revocation has been solved since the Bluray era using AACS subset difference trees.