http://g7ejphhubv5idbbu3hb3wawrs5adw7tkx7yjabnf65xtzztgg4hcsqqd.onion/html/links/dc-badge.html
If you’re new to the conference you may
be wondering what some of the theatre of entropy is that is being
performed all around you. A part of that is the cryptographic puzzle
challenge, most often referred to as the badge challenge.