ChaosVPN for Playing CTFs

Architecture and Background

ChaosVPN - the American name is AgoraLink - is a tinc based, fully meshed VPN to connect hackerspaces and other hacker related networks for fun, sharing, learning and competition with each other. Its purpose is to provide a trusted, private and secure network with high bandwidth, low latency, without single points of failure. The first intended usage of the network was VoIP, but it has become used for lots of different purposes - whatever works on IPv4 and/or IPv6 works on ChaosVPN.

Vulnerability Analysis

This includes our own root zone .hack. Most major Hackerspaces in Europe and America are now connected via the ChaosVPN. To play CTF contests we decided to build a separate incarnation of this network called warzone.

Exploitation and Demonstrations

This network is to compete, play and learn in an isolated environment without harming anyone. We host CTF hacking contests and challenges on the network. Critical thinking, source code analysis, reverse engineering and a good understanding of networks are the abilities honed in this environment.

Remediation and Defensive Strategies

The talk will show the direction ChaosVPN / AgoraLink took and explain some decision points. We will show how it is built, what it does and how to integrate it in your hacker gathering space. And then we will show how this network can be used to play CTF Games and have some fun. Full bio available here: For copies of the slides and additional materials please see the DEF CON 18 Archive here: