Authentication engine and stream cipher engine sharing in digital content protection architectures

A method comprising:

• authenticating, using an authentication engine implemented by a hardware processor, each of a plurality of content channels in sequence, each content channel corresponding to a transmitting device, each transmitting device configured to encrypt media content according to the HDCP protocol and to provide the encrypted media content via the corresponding content channel;
• generating, by the authentication engine, an initial session key corresponding to each of the authenticated content channels;
• receiving encrypted media content on an active content channel of the plurality of content channels, the received encrypted media content comprising a current encrypted frame;
• receiving a session key indicator representative of a current session key used to encrypt the current encrypted frame;
• generating the current session key based on the initial session key corresponding to the active content channel and the received session key indicator;
• and
• decrypting, using a stream cipher engine, the received encrypted media content using at least the generated current session key.

An apparatus comprising:

• a plurality of content channel inputs each configured to receive media content encrypted according to the HDCP protocol over a corresponding content channel;
• and
• an HDCP engine implemented at least in part by a hardware processor comprising:
• an authentication engine configured to sequentially authenticate each content channel and to generate an initial session key corresponding to each authenticated content channel;
• and
• a stream cipher engine configured to decrypt encrypted media content received at an active content channel input based at least in part on a current session key generated at least in part on the generated initial session key corresponding to the content channel corresponding to the active content channel input.