On June 12, 2010 at 17:53, crosen said...
Huh? I'm not certain why you are talking about authentication? I am referring only to the encryption. I fully understand that the AVR communicates with the source for authentication of downstream devices. However, authentication has no bearing on my point.
Perhaps if you could point out a specific aspect of my post that is not correct, that would help resolve this.
You don't understand. I know you think you do. You've been told 3 times yet you still confuse the HDCP authentication with the encrypted data of the high speed data stream. High speed data also includes the audio data stream. This data does not require authentication.
No data is sent till source and sink communicate and authenticate each other. This is done via low speed data or DDC channel. The AVR has nothing to do here but pass this signal on to the sink. It does not look at it. It does not decode it. It does not alter or change keys. It passes the DDC data on to the sink. In fact the source and sink manufacturers have no control over this data. They are purchasing chips and these chips are handling the data handshake. The CE manufacturer is purchasing these chips and allowing data to enter and leave. What happens to this data in these chips he has no control. The return communication from the sink to the source all passes through the AVR without the AVR doing anything to it. These are different data streams. In fact authentication is more akin to serial data. The CE manufacturer will "touch" the high speed data for video and audio but do nothing with the authentication data save pass it from chip to chip.
You might begin to comprehend my questioning of how JAP handles its authentication because they do stop sink and source from authenticating each other.
At the point that source authenticates that the sink is valid the high speed data is sent. If not no data is sent and there's a black screen. It is this data that the AVR is decoding. Even here, it is only the audio portion that it will touch. The audio has its own header and the AVR is parsing the data stream for this header and only stripping out these bits from the data. All the rest is passed on. It may be buffered, parsed and then pushed out. But it's not being retransmitted as you imagine.
These are different data streams. Authentication data is low speed and has nothing to do with the audio and video data streams. The AVR never does anything to the low speed data. Once the high speed data begins to pass from source to sink the AVR will parse this data without destroying it. Holding the data in a buffer while parsing it and then passing it back out to sink is not retransmission.
Alan
