Argh! This quest just keeps getting more complicated!
It's not really complicated... though it helps that I happen to know about certificate chains like this. Admittedly just amateur knowledge, but it stands out to me as such.
To try and explain it more simple though, certificates are used as a way to ensure that at each step a trusted source, emphasis 'trusted' can check to see that what they received indeed came from who it was claimed to be. As well as that the source can be trusted to give you good information.
This means that 'physics' having a certificate doesn't make much sense, why would you trust 'physics' to give you a key? Or give you a good patch update for say your OS? In that regard if you say used a microsoft OS, you'd probably prefer to have a certificate from microsoft confirming it indeed is from microsoft. And if not microsoft, well if say the USA had a certificate and stood in instead for them one level higher (Because for some reason you couldn't get it directly from microsoft), that's probably trustable as well right?
Thus in the end what you have is chains of trust between people. Where if need be you have trusted intermediary parties who can also give you a trustable block of information, patch or otherwise.
And thus basically how higher up the chain you have to go with key, how further removed you are in a sense. (To long a chains might make you thus distrust things again, because how well can you trust each person in the chains judgement after all?)
(This explanation is not wholly correct, but it's the best I can do while keeping it simple at this point of time. It should be close enough I believe)
In this regard you can thus conclude that there was an entity/person with a vname of rindler, that gave out keys two to separates entities/people, that then gave out keys yet again, and those then gave out keys to others yet again, etc, until we reach the required number of steps as indicated by the level. (Again an over simplification, but it will do)