Conference 39th Chaos Communications Congress

One

Protecting the network data of one billion people: Breaking network crypto in popular Chinese mobile apps (en)

Mona

In this talk, I will describe how my team and I systematically exploited around a dozen home-rolled network encryption protocols used by popular mobile apps like RedNote, Alipay, and some of the most popular mobile browsers in China to encrypt sensitive information. I'll demonstrate how network eavesdroppers could access users' browsing history and mobile activity. This is a systemic issue; despite our work on the above protocols and the resulting vulnerability disclosures, this plague of home-rolled and proprietary encryption is still at large. I will end by discussing how we got here, re-affirm the age-old adage, “Don’t roll your own crypto!”, and call on hackers around the world to help us move towards HTTPS everywhere.

Skynet Starter Kit: From Embodied AI Jailbreak to Remote Takeover of Humanoid Robots (en)

Shipei Qu, Zikai Xu, Xuangan Xiao

We present a comprehensive security assessment of Unitree's robotic ecosystem. We identified and exploited multiple security flaws across multiple communication channels, including Bluetooth, LoRa radio, WebRTC, and cloud management services. Besides pwning multiple traditional binary or web vulnerabilities, we also exploit the embodied AI agent in the robots, performing prompt injection and achieve root-level remote code execution. Furthermore, we leverage a flaw in cloud management services to take over any Unitree G1 robot connected to the Internet. By deobfuscating and patching the customized, VM-based obfuscated binaries, we successfully unlocked forbidden robotic movements restricted by the vendor firmware on consumer models such as the G1 AIR. We hope our findings could offer a roadmap for manufacturers to strengthen robotic designs, while arming researchers and consumers with critical knowledge to assess security in next-generation robotic systems.

Chaospager - How to construct an Open Pager System for c3 (en)

Max, Julian

In this talk, we will give an introduction into the project (i.e. how it all started at 38c3 and why we are here now), provide an in-depth review of how the development process of our pager worked and what our future goals are. In our introduction, we will talk about the origin and exploration phase of the inital pager idea (i.e. how we went from the idea of bringing POCSAG Pager transmitter to 38c3, over a cable-bound prototype, to a first working pager on a proper PCB). We will also present our plans of connecting our POCSAG transmitter infrastructure to THOT (CERTs own dispatch software). For our in-depth review about the project, we explain how we encountered major reception problems, how we analyzed them at easterhegg22 and conducted experiments there, and why we are opting for a custom HF frontend design instead of an already-made one from chinese vendors. Moreover, we provide an overview of our transmitter devices and give some advice on how to replicate those. Lastly, we will discuss further challenges and what our next goals are. If we are reaching our milestone until 39c3, we will also give a live demo of the system.

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.

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.

freiheit.exe - Utopien als Malware (de)

Christiane Mudra

"freiheit.exe“ ist eine Lecture über die ideologischen Rootkits des Silicon Valley. Sie schlägt den Bogen von den italienischen Futuristen zu den heutigen Tech-Feudalisten, vom Akzelerationismus zur Demokratieskepsis der Libertären, von Tolkien zur PayPal-Mafia. Basierend auf den Recherchen zu meinem Theaterstück "freiheit.exe. Utopien als Malware", in dem journalistische Analyse auf performative Darstellung trifft.

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

A space odyssey #2: How to study moon rocks from the Soviet sample return mission Luna 24 (en)

Paul Koetter

It is 1976 and the USA long stopped going to the Moon when a Soviet automatic landing station called Luna 24 descends to the Lunar surface. It touches down on 3.3 Billion year old rock formations at a place no mission has ever gone before. What exactly happened remains a mystery to this day, but the space probe managed to take a 2.3 m long drill core from the Lunar regolith, packaged the sample in a genius way and launched it for its voyage to Earth. Some days later the sample entered earths atmosphere and landed in remote Siberia and ended up in our hands more than 50 Years later. We tell the story of the sample, the people that brought it to Earth and how we analyzed it with the newest methods including µm sized high intensity X-ray beams, 30kV electron beams and LN2 cooled infrared spectrometers.

Chaos Communication Chemistry: DNA security systems based on molecular randomness (en)

Anne Lüscher

**Over the past few decades, nucleic acids have increasingly been investigated as alternative data storage media and platforms for molecular computing. This talk builds on past research and introduces another branch to the field: DNA cryptography based on random chemistry. This technology provides a platform for conceiving new security architectures that bridge the physical with the digital world.**

Persist, resist, stitch (en)

Philo

What does knitting have to do with espionage? Can embroidery help your mental health? This talk shows how the skills to create textile art have enabled people to resist and to persist under oppressive regimes for centuries. And it offers ways to keep doing so.

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.

CSS Clicker Training: Making games in a "styling" language (en)

Lyra Rebane

CSS is a programming language, and you can make games in it. Let's install NoScript and make some together!

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.

Zero

Agentic ProbLLMs: Exploiting AI Computer-Use and Coding Agents (en)

Johann Rehberger

This talk demonstrates end-to-end prompt injection exploits that compromise agentic systems. Specifically, we will discuss exploits that target computer-use and coding agents, such as Anthropic's Claude Code, GitHub Copilot, Google Jules, Devin AI, ChatGPT Operator, Amazon Q, AWS Kiro, and others. Exploits will impact confidentiality, system integrity, and the future of AI-driven automation, including remote code execution, exfiltration of sensitive information such as access tokens, and even joining Agents to traditional command and control infrastructure. Which are known as "ZombAIs", a term first coined by the presenter as well as long-term prompt injection persistence in AI coding agents. Additionally, we will explore how nation state TTPs such as ClickFix apply to Computer-Use systems and how they can trick AI systems and lead to full system compromise (AI ClickFix). Finally, we will cover current mitigation strategies and forward-looking recommendations and strategic thoughts.

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.

Variable Fonts — It Was Never About File Size (en)

Bernd

A brief history of typographic misbehavior or intended and unintended uses of variable fonts. Nine years after the introduction of variable fonts, their most exciting uses have little to do with what variable fonts originally were intended for and their original promise of smaller file sizes. The talk looks at how designers turned a pragmatic font format into a field for experimentation — from animated typography and uniwidth button text to pattern fonts and typographic side effects with unintended aesthetics. Using examples from projects such as TypoLabs, Marjoree, Kario (the variable font that’s used as part of the 39C3 visual identity), and Bronco, we’ll explore how variable fonts evolved from efficiency tools into creative systems — and why the most interesting ideas often emerge when technology is used in unintended ways.

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.

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.

Machine Vision – Vom Algorithmus zum Baumpilz im digitalen Metabolismus (de)

Thomas Knüsel

Milliarden von Kameras produzieren täglich Bilder, die zunehmend von Maschinen analysiert werden. In dieser Lecture Performance beleuchten wir die Entwicklung des maschinellen Sehens – von den frühen algorithmischen Ansätzen bis zu den heutigen Anwendungen – und schauen, wie verschiedene Künstler:innen diese Technologien nutzen und reflektieren. Anhand der beiden Arbeiten „Throwback Environment” und „Fomes Fomentarius Digitalis” betrachten wir die Nutzung des maschinellen Sehens in einem künstlerischen Feedback-Loop. Die Arbeiten machen sichtbar, was die eingesetzten Algorithmen sehen und in welchen Mustern sie operieren.

Am Spätverkauf

A blast from the Y2K past… GRÜNSPAN (Rock & Metal) (en)

Alex Thurow

A time travel DJ set back to the times of the millennium change… … to the times of the prevented [Y2K apocalypse](https://en.wikipedia.org/wiki/Year_2000_problem) … to the times of the [Dot-com bubble](https://en.wikipedia.org/wiki/Dot-com_bubble) (… it’s about time AI, isn’t it?) … to the times of a [VERY problematic seed being planted](https://en.wikipedia.org/wiki/2000_Russian_presidential_election) … but most importantly to the times of the glorious: [| G.--. || R.--. || Ü.--. || N.--. || S.--. || P.--. || A.--. || N.--. |](https://www.gruenspan.de/) Back when ROCK was alive and kickin’ in „Hamburg meine Perle“! So, if you want to get a LOUD blast from the past - come join us and bring your [Pommesgabel](https://de.wikipedia.org/wiki/Mano_cornuta) with you! Live long and prosper, [DJ Alex](https://mstdn.social/@alexthurow/110279531725018974) (AKA: [https://onmoderndev.de](https://onmoderndev.de))

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

chaeza + doc (de)

chaeza + doc

Dj Set

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