If you go back and read some of what I've written it will seem as if my argument is changing. It's not that I'm attempting to mislead nor am I trying to play games. I am trying to get to see the flow chart without adding further confusion. I edited out encryption of the TMDS because I felt it would move you away from what is happening schematically even if it wasn't completely accurate technically. You continue to focus on the irrelevant. How data is encrypted and read is irrelevant to our installations. You need to understand the process to see where it's been hung up and where to fix it.

Yes, the data is encrypted. The keys are part of this process. Yet the only place it is relevant is for a manufacturer understanding how many keys he needs to purchase for his product to work in a system. The source is simultaneously dealing with keys from sinks and repeaters. The are multiple "links" established. Even while it's technically incorrect my description of the keys as a means of opening a door to validate a system as legal is the best way to understand the process. All devices announce themselves and each will pass their keys to source. But it's not pertinent to understanding the encryption/decryption process nor is it useful in diagnosing a system and fixing it.

Source authenticates sink. Source will accept X amount of keys as valid in a system where X is the number of keys a manufacturer has chosen to support ( purchase ). Source will accept as valid Y number of repeaters in a system which is a function of the protocol. However, why do you think any of this of any importance? This is an academic exercise? You need to understand why the HDCP and EDID handshake work. You further need to understand that there is an audio handshake as part of the EDID handshake and this is the part most susceptible to failure when there are issues on the low speed data bus.

Here is what I think you need to know from the point of view of a CI. Did the HDCP handshake make it? Did the EDID handshake make it? If so you will have a picture. If you are expecting audio and you have the former 2 but no audio you have an EDID issue to solve.

If you have sparkles or the colors are off you have issues with the high speed data bus.

Why do you care at all how devices read the data? You do want to be mindful that there are a finite number of devices that a source will permit before deciding the system is illegal and turning off video. How the repeater strips off the data is important how? For what reason? You're on to a side show that will not help you install, sell or troubleshoot. You are getting lost in the tree of details when you ought to be focusing on the forest.