CRITICAL 
DECENTRALIZATION
CRITICAL 
DECENTRALIZATION
CRITICAL 
DECENTRALIZATION

The Critical Decentralisation Cluster (CDC) is returning to the 39th Chaos Communication Congress in Hamburg (Germany) during Dec 27-30 2025. We bring together assemblies and projects that challenge centralized infrastructures with decentralised, privacy-preserving and open hardware approaches. Expect talks, workshops and lots of hallway conversations around cypherpunk futures.

assemblies

  • RIAT - independent research institute in Vienna
  • Monero Community
  • Namecoin - decentralized tamper-resistant naming system + PKI
  • Swiss Cryptoeconomics
  • I2P - fully encrypted peer-to-peer overlay network
  • Cyberraum - hackers’ group from Hamburg
  • Radicle - peer-to-peer code collaboration stack built on Git
  • Social Dist0rtion Protocol - ad-hoc riddles and games
  • GNU Boot - de-shittification for your BIOS and UEFI
  • Department of Decentralisation - collective from Berlin
  • Firo - independent blockchain privacy and decentralization tech research
  • Iroh - library and protocol stacks to build next-gen P2P networks
  • FOSSASIA - open-source community in Asia
  • Off-Grid Messaging - independent networks over LoRa and packet-radio
  • Sibermerdeka - hackerspace in Kuala Lumpur
  • Replicant - fully free Android distribution
  • Auditable silicon group TROPIC01 - open-source IC designers
  • Reticulum - resilient cryptography-based networking stack
  • Infinite Build - a peer-support group for builders
  • Crypto Commons - P2P technologies for the stewardship of common goods
  • BORDEL - hackerspace in Prague
  • Gosling - P2P over Tor onion services
  • Cat Pictures Data Distribution Hub - challenges with cute kitty pictures as rewards
  • Nitrokey - Open Source IT security hardware
  • XMPP - the open standard for messaging and presence

We welcome other assemblies in the categories Privacy & Anonymity, Enshittification, Cryptography, Open and Verifiable Hardware and Peer-to-Peer (P2P) networks and tools.

sessions

The CDC features 2 workshop areas with public schedule.
https://pretalx.riat.at/39c3/schedule

The CDC Triangle is equipped with a mini-stage and recording equipment for short talks.
The CDC Circle has 3 screens and no recording.

Last minute submissions are open at pretalx.riat.at.

location

The CDC is located in Hall H: https://39c3.c3nav.de/l/cdc/@0,189.91,122.12,4.34

It has:

  • tables and seats for ca. 120 people
  • 2 info tables and meeting spots
  • 2 workshop areas

contributing

Volunteer work is essential to keep the cluster going.
Checkout Volunteering at the CDC for more information.

contacts