Cryptanalysis

Hello, I’m trying to do some cryptoanalysus challenges but I’m blocked. What I need to do ?

Hello,
You can read documents associated with each challenges,
use your favorite search engine to get more information with the info you have with the challenge description,
be a little more specific on where you are blocked so we can help you (without spoiling anything),
go on the irc channel (https://www.root-me.org/en/Community/IRC-channel/) to ask for help if you really are blocked on a challenge.

Hope that will help.
Good luck !