Conference 39th Chaos Communications Congress

One

Constanze Kurz, khaleesi, Matthias Marx, Linus Neumann, erdgeist

Das war nicht das Jahr 2025, das wir bestellt hatten.

Verlorene Domains, offene Türen - Was alte Behördendomains verraten (de)

Tim Philipp Schäfers (TPS)

Was passiert, wenn staatliche Domains auslaufen - und plötzlich jemand anderes sie besitzt? In diesem Vortrag wird berichtet, wie mehrere ehemals offizielle, aber unregistrierte Domains deutscher Bundesministerien und Behörden erworben werden konnten - und welche Datenströme dadurch sichtbar wurden. Über Monate hinweg konnten so DNS-Anfragen aus Netzen des Bundes empfangen werden - ein erhebliches Sicherheitsrisiko. Unter anderem da es so möglich war Accounts zu übernehmen, Validierungen von E-Mailsignaturen zu manipulieren, Anfrage umzuleiten und im Extremfall Code auf Systemen auszuführen. (Keine sensiblen Daten werden veröffentlicht; der Fokus liegt auf Forschung, Aufklärung und verantwortungsvollem Umgang mit den Ergebnissen.)

Don’t look up: There are sensitive internal links in the clear on GEO satellites (en)

Nadia Heninger, Annie Dai

We pointed a commercial-off-the-shelf satellite dish at the sky and examined all of the geostationary satellite communications visible from our vantage point. A shockingly large amount of sensitive traffic is being broadcast unencrypted, including critical infrastructure, internal corporate and government communications, private citizens’ voice calls and SMS, and consumer Internet traffic from in-flight wifi and mobile networks.

Ground

Burn Gatekeepers, not Books! (de)

tomate, jinxx

*Der deutsche Buchmarkt gegen den Rest der Welt oder auch: Enshittification des Buchmarkts und keine API für ein Halleluja* Es gibt unzählige wundervolle Geschichten und das Internet hat über die letzten Jahrzehnte viele großartige Autor*innen hervorgbracht. Doch Verlage haben begrenzte Kapazitäten und sind außerdem zumeist sehr konservativ in ihren Programmen. Die Lösung für beides: Selfpublishing. Neue und gewitzte, genre-übergreifende Bücher an neugierige Lesende zu bringen, könnte so einfach sein; wären da nicht Barsortimente, fehlende APIs und ein insgesamt schreckliches Ökosystem, die Indie-Autor:innen (und alle, die versuchen, auf dem deutschpsprachigen Buchmarkt irgend etwas Innovatives für Indies zu machen) das Leben schwer machen.

Current Drone Wars (en)

Leonard

The character of drone wars has changed. The large, cumbersome long-range drones have been complemented with small and low-budget drones. Moreover, more and more states are developing, deploying and selling them. Ten years ago at least 50 states were developing them. At the top are USA, Israel, Turkey, China, Iran and Russia. Russia's attack on Ukraine has unleashed a drone war unlike any seen before. In short time the Ukraine has build significant drone production capabilities and announcement that it will increase its own production of quadcopters and kamikaze drones to one million units per year. German defense companies and startups are now promoting a “drone wall on NATO's eastern flank.” Moreover, despite their vulnerability to air defenses, large drones are also being further developed. They are intended to accompany next generation fighter jets in swarms. In this talk, past and current developments are discussed. What are the perspectives now?

Recharge your batteries with us - an empowering journey through the energy transition (en)

Salacidre, JulianeB

Amidst gloomy headlines, extreme weather, and climate anxiety, the good stories often get lost. Yet they exist - inspiring people, clever engineering, real breakthroughs. And that's exactly what we bring you – the positive power cycles of the energy transition in action. And real energy on stage.

Zero

Amtsgeheimnis raus, Datenhalde rein: was die Informationsfreiheit in Österreich bringt (de)

Markus (fin) Hametner, Erwin Ernst "eest9" Steinhammer

Jahrelang war die staatliche Intransparenz in Österreich nur eine Punchline in den Congress-Talks von Frag Den Staat. Damit könnte jetzt Schluss sein: seit heuer haben Bürger:innen endlich ein Recht, Dokumente einzusehen und ein Informationsfreiheitsgesetz. Wir zeigen, was Deutschland aus der über ein Jahrzehnt andauernden Kampagne für die Abschaffung des Amtsgeheimnisses lernen kann, wofür uns die Nachbarländer beneiden werden und wofür sich Bayern besonders schämen sollte.

How To Minimize Bugs in Cryptography Code (en)

Jade

"Don't roll your own crypto" is an often-repeated aphorism. It's good advice -- but then how does any cryptography get made? Writers of cryptography code like myself write code with bugs just like anyone else, so how do we take precautions against our own mistakes? In this talk, I will give a peek into the cryptographer's toolbox of advanced techniques to avoid bugs: targeted testing, model checking, mathematical proof assistants, information-flow analysis, and more. None of these techniques is a magic silver bullet, but they can help find flaws in reasoning about tricky corner cases in low-level code or prove that higher-level designs are sound, given a defined set of assumptions. We'll go over some examples and try to give a high-level feel for different workflows that create "high-assurance" code. Whether you know it or not, you use this type of cryptography code every day: in your browser, your messaging apps, and your favorite programming language standard libraries.

When Vibe Scammers Met Vibe Hackers: Pwning PhaaS with Their Own Weapons (en)

Chiao-Lin Yu (Steven Meow)

What happens when AI-powered criminals meet AI-powered hunters? A technical arms race where both sides are vibing their way through exploitation—and the backdoors write themselves. In October 2025, we investigated Taiwan's fake delivery scam ecosystem targeting convenience store customers. What started as social engineering on social media became a deep dive into two distinct fraud platforms—both bearing the unmistakable fingerprints of AI-generated code. Their developers left more than just bugs: authentication flaws, file management oversights, and database implementations that screamed "I asked LLM and deployed without reading." We turned their sloppiness into weaponized OSINT. Through strategic reconnaissance, careful database analysis, and meticulous operational security, we achieved complete system access on multiple fraud infrastructures. By analyzing server artifacts and certificate patterns, we mapped 100+ active domains and extracted evidence linking thousands of victim transactions worth millions of euros in fraud. But here's the twist: we used the same AI tools they did, just with better prompts. The takeaway isn't just about hunting scammers—it's about the collapse of the skill gap in both offense and defense. When vibe coding meets vibe hacking, the underground economy democratizes in ways we never anticipated. We'll share our methodology for fingerprinting AI-assisted crime infrastructure, discuss the ethical boundaries of counter-operations, and demonstrate how to build sustainable threat intelligence pipelines when your adversary can redeploy in 5 minutes. This talk proves that in 2025, the real exploit isn't zero-day—it's zero-understanding.

The Small Packet of Bits That Can Save (or Destabilize) a City (en)

Manuel Rábade

The Emergency Alert System (EAS) and its SAME (Specific Area Message Encoding) protocol are public alerting technologies that broadcast short digital bursts over VHF triggering emergency messages on millions of receivers across North America. In Mexico, this technology was integrated into the Seismic Alert System (SASMEX) which more than 30 million people in the central part of the country rely on to prepare for frequent earthquakes. While new alerting technologies have emerged, the EAS-SAME network continues to play an important role for public safety in the U.S., Mexico, and Canada. Yet, the same small packets of bits that can help protect a city could also, in the wrong hands, destabilize it. This talk examines how these systems operate and reveals a troubling truth: spoofing these alerts is far easier than most people expect.

Fuse

Über europäische Grenzen hinweg auf klinischen Daten rechnen - aber sicher! (de)

Hendrik Ballhausen

Der Trend geht dahin, aus Gesundheitsdaten große zentralisierte Datenbanken aufzubauen. Eine datensparsame Alternative dazu ist, in einem verschlüsseltem Netzwerk gemeinsam auf verteilten privaten Daten zu rechnen, ohne sie miteinander teilen zu müssen. Perspektivisch können so demokratischere Datenströme geschaffen werden, die Patient:innen als aktiv Teilhabende statt als passive Datenquellen einbinden. Kommt mit auf eine Reise, die vor sechs Jahren in Deutschland gestartet ist und jetzt die erste europäische klinische Studie mit Secure Multiparty Computation (SMPC) realisiert hat.

Auf die Dauer hilft nur Power: Herausforderungen für dezentrale Netzwerke aus Sicht der Soziologie (de)

Marco Wähner

Der Vortrag diskutiert Herausforderungen dezentraler Netzwerke aus soziologischer Perspektive. Als dezentrale Netzwerke werden technische Infrastrukturen verstanden, die nicht von einer zentralen Autorität, sondern verteilt über Instanzen zur Verfügung gestellt werden. Nutzer:innen profitieren von dieser Infrastruktur, nutzen beispielsweise das Fediverse oder das Tor-Netzwerk, ohne zur Infrastruktur beizutragen. Zugleich können dezentrale Netzwerke nur dann bestehen, wenn hinreichende Ressourcen von Personen oder Organisationen mobilisiert werden, um das Netzwerk überhaupt zur Verfügung zu stellen. Dies führt zur originären Instabilität dezentraler Netzwerke, wenn nicht der Weg der Kommodifizierung des Nutzer:innenverhaltens eingeschlagen wird. Aufbauend auf dieser Zustandsbeschreibung, werden Bedingungen erörtert, um Kollektivgüter wie dezentrale Netzwerke organisatorisch (und nicht technisch) herzustellen. Hierzu zählen Partizipation oder die Idee einer öffentlichen Grundfinanzierung. Der Vortrag wird neben soziologischen Ideen und harten Zahlen auch durch eine ordentliche Portion Idealismus zu Fragen der Souveränität und Autonomität in der Digitalisierung motiviert.

A Quick Stop at the HostileShop (en)

Mike Perry

HostileShop is a python-based tool for generating prompt injections and jailbreaks against LLM agents. I created HostileShop to see if I could use LLMs to write a framework that generates prompt injections against LLMs, by having LLMs attack other LLMs. It's LLMs all the way down. HostileShop generated prompt injections for a winning submission in OpenAI's GPT-OSS-20B RedTeam Contest. Since then, I have expanded HostileShop to generate injections for the entire LLM frontier, as well as to mutate jailbreaks to bypass prompt filters, adapt to LLM updates, and to give advice on performing injections against other agent systems. In this talk, I will give you an overview of LLM Agent hacking. I will cover LLM context window formats, LLM agents, agent vulnerability surface, and the prompting and efficiency insights that led to the success of HostileShop.

How to render cloud FPGAs useless (en)

Dirk

While FPGA developers usually try to minimize the power consumption of their designs, we approached the problem from the opposite perspective: what is the maximum power consumption that can be achieved or wasted on an FPGA? Short answer: we found that it’s easy to implement oscillators running at 6 GHz that can theoretically dissipate around 20 kW on a large cloud FPGA when driving the signal to all the available resources. It is interesting to note that this power density is not very far away from that of the surface of the sun. However, such power load jump is usually not a problem as it will trigger some protection circuitry. This led us to the next question: would a localized hotspot with such power density damage the chip if we remain within the typical power envelope of a cloud FPGA (~100 W)? While we could not “fry” the chip or induce permanent errors (and we tried several variants), we did observe that a few routing wires aged to become up to 70% slower in just a few days of stressing the chip. This basically means that such an FPGA cannot be rented out to cloud users without risking timing violations. In this talk, we will present how we optimized power wasting, how we measured wire latencies with ps accuracy, how we attacked 100 FPGA cloud instances and how we can protect FPGAs against such DOS attacks.

Trump government demands access to European police databases and biometrics (en)

Matthias Monroy

The USA is demanding from all 43 countries in the "Visa Waiver Programme" (VWP), which enables visa-free travel, to conclude an "Enhanced Border Security Partnership" (EBSP). This is intended to grant US authorities direct access to police databases in these - mostly European - countries containing fingerprints, facial images and other personal data. Anyone who refuses this forced "border partnership" faces exclusion from the visa-free travel programme.

Power Cycles statt Burnout – Wie Einflussnahme nicht verpufft (de)

Rahel Becker, Anna Kassautzki

Zwischen offenen Briefen, Massenmails, Petitionen und Kaffee trinken : Zwei Ex-Insiderinnen aus dem Digitalausschuss und Bundestag erzählen, wie politische Einflussnahme wirklich funktioniert. Ein ehrlicher Blick hinter die Kulissen parlamentarischer Entscheidungsfindung – mit praktischen Tipps, wie die Zivilgesellschaft ihre Energie dort einsetzt, wo sie wirklich Wirkung entfaltet.

Am Spätverkauf

Punkrock-Songtext-Lesung (de)

tomate, anna

Kultivierte Personen rezitieren Punkrock-Songtexte mit der ganzen Ernsthaftigkeit und dem dramatischen Pathos, wie sonst nur von Goethe-Abenden im Literaturhaus bekannt. Anarchie meets Bildungsbürgertum. Chaos meets Chaiselongue.

Antifaschistischer Akkordeon-Punk - Grölen gegen Rechts (de)

Pianostein

Klassiker des antifaschistischen Deutschpunk-Liedguts – von Die Ärzte über Die Toten Hosen bis WIZO und Terrorgruppe – neu interpretiert auf dem Akkordeon. Laut, links und garantiert mitgröltauglich.

Chaos Computer Music Club

The 39c3 Drag Show (en)

Keks

Finally a drag show at the chaos! Blinking lights, colorful outfits, and queers everywhere already seems normal at the congress. So how can it be, that all of this did not come together as drag on stage?! It is time for a really awesome, great drag show at the 39c3! And to show right away how divers drag is, a wonderful cast of drag artists of various genders and expressions can spread their queer joy and art for the audience. The show is hosted by Milky Gay, the nerdiest drag king from NRW, who does not only want to throw glitter at the congress incognito this year. And he is bringing an amazing cast with him Bingus Bongus (Drag Queen, Hamburg) Neuro Spicy (Drag King, NRW) Missass Nostalgia (Drag Queen, NRW) and Kaín Mensch (Drag Thing, Hamburg) will bring their queer art to finally merge chaos and drag! Everyone is welcome, we are trying to have as little barriers as possible to come and watch. No blinking lights during the show (no guarantee for the path there and acts before and after), Music Club accessible with mobility aids and wheel chairs (ask assigned angles). Mostly standing room, few seats at the side might not allow for a good view of the show. Content notes for certain parts of the show include death, cancer, violence, fake weapons, and sexual violence, and will be announced in time so people can leave and come back afterwards. Cheering is encouraged, so it might get loud. (more details tba). Please be nice to each other and especially help short people as well as queers to find a spot where they can see enough. Also, as drag is expensive, there will be a tipping round in the end - please bring some cash if you consider tipping the artists, but of course you are also welcome either way.

Kenji Tanaka Live (en)

Kenji Tanak

In my improvised live set, my random generators and I bounce ideas off each other. This approach allows previously created loops to flow into endless new combinations.

Chill Floor

Lila-Zoé Krauß (de)

Lila-Zoé Krauß

L Twills aka Lila-Zoé Krauß ist Musikerin, Performerin und Multimedia-Künstlerin. In ihrer Arbeit entwickelt sie eine transdisziplinäre Opernpraxis, um Fragen zur (post-)moderner Subjektivität und ihrer Beziehung zu Medien, Trauma und Erinnerung zu thematisieren. Sie studierte Bildende Kunst an der HFBK Hamburg und dem CalArts Los Angeles sowie Sound Studies an der UdK Berlin. In ihrer Musik kombiniert sie Elemente aus Downtempo, Experimentalmusik, Breakbeat und Oper mit eigens entwickelten Sounddesign-Techniken. Krauß veröffentlichte 2020 und 2024 die Vinylalben [Freedom/Fiction] und [After her Destruction] und performte auf diversen Bühnen, u.a.: Documenta Fifteen (Kassel), Kampnagel (Hamburg), Volkstheater (Wien), Montez-Press Radio (NYC), NAVEL (Los Angeles).

Gajek (de)

Unnamed user

Gajek produces and performs electronic music. Since 2014 He released five studio albums on Labels such as STROOM, Infinite Greyscale, Throttle Records and more. Gajek composes music for films and theatre. He has performed at major international venues and festivals such like Berghain, silent green, Printworks London, Traumabar Und Kino, ADE Amsterdam, Melt Festival and many more. Gajek lives and works in Berlin.

Theme

Schedule