Any good cipher communities or sources?

I recently completed Nadya’s ctf (up until the ninth part). I thoroughly enjoyed the cipher aspect of the CTF. This got me thinking, are there any good similar CTFs lainons would recommend? Any good active communities I could take a look at? Bonus points if they require a puzzle to be solved in order to join.

I can't pass the level 0. Can you give some hints? I used an online decipher tool and obtained somewhat meaningful text out of it. But now i have no idea what to do next

>>22400 I think i have the entrance flag, how dose one submit a flag?

Nadya's ctf seems interesting, wouldn't have found it without this thread But much like the other lainon I am confused as to how / where to enter the flags to progress