Conference 39th Chaos Communications Congress

One

Cracking open what makes Apple's Low-Latency WiFi so fast (en)

Henri Jäger

This talk presents Apple's link-layer protocol Low-Latency WiFi and how it achieves its real-time capabilities to enable Continuity features like Sidecar Display and Continuity Camera. We make more kernel logging available on iOS and build a log aggregator that combines and aligns system- and network-level log sources from iOS and macOS.

CCC-Jahresrückblick (de)

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

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

In-house electronics manufacturing from scratch: How hard can it be? (en)

Augustin Bielefeld, Alexander Willer

Why is electronics manufacturing hard? Can it ever be made easy and more accessible? What will it take to relocate industrial production to Europe? We share with you what we learned when we spent more than 1 year setting up our own production line in our office in Hamburg. Turns out a lot of the difficulties are rarely talked about or hidden behind "manufacturing is high CAPEX". Come and learn with us the nitty gritty details of batch reflow ovens, stencil printing at scale, and how OpenPnP is a key enabler in our process. While we are far from done with this work, we hope to see others replicate it and collectively reclaim the ownership of the means of electronics production.

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.

Xous: A Pure-Rust Rethink of the Embedded Operating System (en)

bunnie, Sean "xobs" Cross

Xous is a message-passing microkernel implemented in pure Rust, targeting secure embedded applications. This talk covers three novel aspects of the OS: hardware MMU support (and why we had to make our own chip to get this feature), how and why we implemented the Rust standard library in Rust (instead of calling the C standard library, like most other Rust platforms), and how we combine the power of Rust semantics with virtual memory to create safe yet efficient asynchronous messaging primitives. We conclude with a short demo of the OS running on a new chip, the "Baochip-1x", which is an affordable, mostly-open RTL SoC built in 22nm TSMC, configured expressly for running Xous.

Ground

CPU Entwicklung in Factorio: Vom D-Flip-Flop bis zum eigenen Betriebssystem (de)

PhD (Philipp)

Factorio ist ein Fabriksimulationsspiel mit integriertem Logiksystem. Dies ermöglichte mir den Bau einer CPU, die unter anderem aus einer 5-stufiger Pipeline, einer Forwarding Logikeinheit, Interrupt Handling sowie einem I/O Interface besteht. Über einen selbst geschriebenen Assembler konnte ich ein eigenes Betriebssystem und Programme wie Minesweeper oder Snake integrieren. Der Talk soll euch zeigen, wie sich klassische Computerarchitektur in einem völlig anderen technischen Kontext umsetzen lässt und wo dabei überraschend echte Probleme der CPU-Entwicklung auftreten. Kommt mit auf die Reise: Vom Blick auf den gesamten Computer bis hinunter zu den einzelnen Logikgattern ist es nur eine Mausradbewegung entfernt!

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.

Textiles 101: Fast Fiber Transform (en)

octoprog

Textiles are everywhere, yet few of us know how they’re made. This talk aims to give you an overview over the complete transformation from fiber to finished textile. We'll be exploring fiber properties, spinning, and techniques like weaving, knitting, crochet, braiding, and knotting, followed by finishing methods such as dyeing, printing, and embroidery. You’ll learn why not only fiber but also structure matters, and how to make or hack textiles on your own without relying on fast fashion or industrial tools.

Reverse engineering the Pixel TitanM2 firmware (en)

willem

The TitanM2 chip has been central to the security of the google pixel series since the Pixel 6. It is based on a modified RISC-V design with a bignum accelerator. Google added some non standard instructions to the RISC-V ISA. This talk investigates the reverse engineering using Ghidra, and simulation of the firmware in python.

Zero

Amateurfunk im All – Kontakt mit Fram2 (de)

akira25, flx, Gato

Wir geben Einblicke in zwei intensive Wochen Planung, Koordination und Aufbau, den Betrieb einer (improvisierten) Bodenstation, sprechen über technische Hürden, Antennendesign und Organisation – und wie wir schließlich mit Astronautin Rabea Rogge im Weltraum gefunkt haben.

Lessons from Building an Open-Architecture Secure Element (en)

Jan Pleskac

The talk will be about our experience from building an open-architecture secure element from the ground up. It explains why openness became part of the security model, how it reshaped design and development workflows, and where reality pushed back — through legal constraints, third-party IP, or export controls. It walks through the secure boot chain, attestation model, firmware update flow, integration APIs, and the testing framework built for external inspection. Real examples of security evaluations by independent researchers are presented, showing what was learned from their findings and how those exchanges raised the overall security bar. The goal is to provoke discussion on how open collaboration can make hardware more verifiable, adaptable, auditable and while keeping secure.

Prometheus: Reverse-Engineering Overwatch (en)

breakingbread

This talk explores the internals of Overwatch which make the game work under the hood. The end goal is to democratise development of Overwatch. Being able to host your own servers and modify the game client to your liking should not be up for discussion for a game many people have paid money for.

Wie wir alte Flipperautomaten am Leben erhalten (de)

Axel Böttcher

Der Vortrag beschreibt, wie eine Gruppe von Begeisterten eine Sammlung von ca. 100 Flipperautomaten (Pinball Machines) am Leben und in spielbereitem Zustand erhält.

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.

The Maybe Talent Show (en)

Norman Müller-Schmitz, lukas-schmukas, James Bonne d'age

Come on stage and present things you are very bad in. Or just mediocre. Get raging applause and love from the audience! Hosted by the drag-quings Norman Müller-Schmitz and James Bonne d'age this open stage celebrates trying, failing and the beauty of discovering hidden Talents together when the most beautiful cuties from the audience enter the stage to try something they have absolutely no experience in.

Am Spätverkauf

4ever punk (en)

DJ Baba Grande

one hour of punk music, encompassing many different styles

Chaos Computer Music Club

Sportbrigade Sparwasser (de)

Hüp Now

We are well aware of the fact, that as DJs we play other peoples´(as well as our own) music. This means we want to ensure the musicians get the credit and respect they deserve for their work. Whenever reasonably possible (communication get quite intense for us at times) we´ll be happy to supply track IDs, although sometimes it may take a little while. Also we´re happy about reposts if you like what we´re doing.

Hitstorm aka The Jakob Sister b2b RaverPik (en)

RaverPik

This DJ Team the combines all the Sachsentrance craziness :D since both DJs run the Sachsentrance Label and organize their famous events, widely known for their ecstatic vibes. It's pure Joy!

Chill Floor

Weebz (en)

Weebz

WEEBZ likes to move between the odds, the rough and the soft: Breakbeat, dissonances, noise and sounds of deep dungeons belong to their mixes as well as the hymns of our hearts Most of the time the genres are mixed to an eclectic collection mirroring own confusions in the spirit of making the unmatching matching xx

Fimi & Nush (de)

Hanni

Fimi&Nush

Felix Kubin (de)

Felix Kubin

Felix Kubin, funkensprühender Spannungs- und Weltenwandler aus Hamburg, Verachter der Nüchternheit, lenkt die musikalische Kompassnagel Richtung Stolperdisko, Art Pop und „gute Nervmusik“. Das Tanzbein zappelt, aber die Beine laufen in verschiedene Richtungen, denn sie haben sich noch nicht synchronisiert. Hier erklingen Songs am Rande des Nervenzusammenbruchs, "Musik für junge Leute" und alle, die nicht sterben wollen. Vor allem haben es ihm die obskuren Musikversuche der Heimstudios vergangener Fostex-Generationen angetan, die Art Brut und ihre Einfärbungen durch billige, leicht zu demolierende Technologien. Felix Kubins musikalische Adoleszenz wurde durch eine Zeit geprägt, in der sich die Szenen der Kunst und Musik stark durchdrangen und Songtitel wie "Die Gesunden kommen", "Adrenalin lässt das Blut kochen" und "Hosen, die nicht aneinander passen" kein Stirnrunzeln verursachten. Eine Zeit also, in der sich die Popmusik weit aus dem Fenster lehnte und die Luft einer fremden, seltsamen Welt atmete.

Vorglühmarkt

Loui Beton (en)

Loui Beton

Lets get besinnlich at the 39C3

Zweite Sahne & Olga Rhythmus (en)

Tesa

A DJ duo from Frankfurt playing technoid Dark Disco. Soundcloud: https://on.soundcloud.com/ieVMVNI9qlqR6BNBHh

Theme

Schedule