In the github comments you speak of a rfc of the actual common coin you’re going to implement (as replacement of the fake one in PR 310). Which rfc is that? I do find #0049 PARSEC, where there is talk of a concrete coin (2/3th of the time common). And that is what I remember (maybe wrongly) as being the (initial) Parsec breakthrough (Byzantine Agreement, Made Trivial), because a common coin was very difficult.
Oops. My bad! I thought we had released an RFC for a proper common coin. We definitely edited the paper to include a real common coin, but haven’t released this yet as it’s making its way through the formal publication process.
We also did a POC of proper common coin but didn’t finish it as we ran out of allocated time to investigate pre-Fleming. We also wrote up the lessons learnt in this POC with the intent to raise a RFC, but it seems we didn’t actually publish it yet.
A common coin is difficult, but now the hard bits are available as other projects such as POA Network released some important components such as Distributed Key Generation in the open. It makes it feasible, now in 2019 to implement and rely on an actual common coin rather than our concrete coin which limited how asynchronous the algorithm was.