I must correct myself, it was neither Bitcoin Dark nor Black, the coin was called Bitcoin Private. Was a direct successor of ZClassic, which was a fork of ZCash, launched by the founder, but this was some years ago.

https://btcprivate.org/ <- Page could be completely down, I don't have it loading at the moment.

Was a mega hype about this project 3 years ago, ZClassic has risen to unbearable heights within this forum. Rhett was the name of the guy, if I remember correctly.

But I have to say that I can't find Rhett on the team list of electriccoin, maybe I confuse these projects just because of the similarity of the names. I would have to check this evening. When I think of it, I'll give you another update here.