Maybe this is not entirely /x/ but I still don't know what this riddle ended up as because I wasn't there to see, and we ended up losing our board >>>/mbwr/ because I forgot it was a thing when 8chan was recovering dead boards after the april 2017 hack, and apparently nobody else cared.
So if anybody was a /b/tard when this happened and can clear shit up that would be nice. It was called the NIL riddle, the results on the internet looking it up are limited. Some /b/tard posted something about a complex riddle on some TOR website that possibly had ties to cicada, this developed into a multiple months long thread/general in which we gathered to solve it and painstakingly advance every step. The questions were difficult but if it was unsolvable I don't know because when I was following things we were progressing at a steady pace. There was the /b/ thread, some shitty VoIP group (maybe discord, I don't really remember) and individual persons independently making progress and leaking information to each other. Everyone wanted to be a step ahead because there was this consensus the winner or winners of the riddle would earn something.
It happened around late 2015, it was definitely organized by some sort of wealthy group because it involved internationally gathering physical information left on the streets by whoever or whatever was orchestrating the whole thing.
After one of the steps of the riddle it provided you with a hash and the people with it were "chosen" or something, supposedly the chosen hashes were relevant to the ending. The number was limited and I was one of the "chosen", this is where my memory gets foggy. Chosen may not be the right term, again, my memory is foggy. We agreed to share information and we gathered in the lost board.
I'm saying it's maybe not entirely /x/ because I'm talking about it like a simple riddle, but again, it was complex enough that it involved international preparation. It required wealth to be spent on something specifically targetting a small board on this website and it wasn't some sort of public event, the consensus was that the riddle was some sort of selection proccess for something.
Whatever information anyone here has would be nice, what I have myself is limited.