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.

A post-American, enshittification-resistant internet (en)

Cory Doctorow

Trump has staged an unscheduled, midair rapid disassembly of the global system of trade. Ironically, it is this system that prevented all of America's trading partners from disenshittifying their internet: the US trade representative threatened the world with tariffs unless they passed laws that criminalized reverse-engineering and modding. By banning "adversarial interoperability," America handcuffed the world's technologists, banning them from creating the mods, hacks, alt clients, scrapers, and other tools needed to liberate their neighbours from the enshittificatory predations of the ketamine-addled zuckermuskian tyrants of US Big Tech. Well, when life gives you SARS, you make sarsaparilla. The Trump tariffs are here, and it's time to pick the locks on the those handcuffs and set the world's hackers loose on Big Tech. Happy Liberation Day, everyone!

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

Hatupangwingwi: The story how Kenyans fought back against intrusive digital identity systems (en)

Mustafa Mahmoud Yousif

The session title is fashioned after the Kenyan movement building rhetoric “Hatupangwingwi” which is Kenyan slang meant as a call to action to counter anti-movement building techniques by the political class and resist infiltration and corruption. This is true for the organisation and movement building towards inclusive identity regimes in Kenya. The session seeks to explore the lessons from Kenya’s journey to digitalization of public services and the uptake of Digital Public infrastructure. It digs deeper on the power of us and how civil society could stop a destructive surveillance driven digitalisation thus protecting millions of Kenyans.

Suing spyware in Europe: news from the front! (en)

Lori Roussey, Celia/Irídia

In 2022, CitizenLab contacted a member of the Spanish non-profit Irídia to tell them that one of their members had likely been hacked with Pegasus spyware. The target, a lawyer, had been spied on by the Spanish government in 2020 because he represented a Catalan politician who was in prison. His phone was infected with Pegasus during the COVID-19 lockdown, on the same day he was having an online meeting with other lawyers working on the case. Irídia and the lawyer (Andreu) decided to take the case to court. A few years later, he met with Data Rights and invited them to join forces and bring in partners from across Europe to increase the impact. This collaboration led to the creation of the PEGA coalition in May 2025. This talk goes over the status of the case and work we have done across Europe to bring spyware use in court.

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.

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.

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?

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!

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.

Live, Die, Repeat: The fight against data retention and boundless access to data (en)

Klaus Landefeld

Both within the EU as well as nationally in Germany, there exists a renewed drive to implement data retention, a practice struck down by the ECJ and discontinued in many national legislations. In parallel, cross-border access to stored data has been mandated within the EU as “e-evidence”, and will soon be extended to 90+ countries under the umbrella of the EU cybercrime convention. In principle, all data stored by service providers will be available to law enforcement as part of a criminal investigation. The timing of both initiatives is not coincidental, as access to data naturally relies on the availability of data. The talk will address the state of play on data retention in various legislations, and introduce the practice of cross border access to stored data by law enforcement as well as its shortcomings and threats to privacy and confidentiality.

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.

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.

Fuse

Digitale Inklusion: Wie wir digitale Barrierefreiheit für alle erreichen können (de)

Jakob Sponholz, Kathrin Klapper, Lena Christina Müller

Könntest du jetzt noch sagen, was du heute online gemacht hast? Für viele ist das Internet so selbstverständlich, dass sie es kaum noch merken, wenn sie es benutzen. Dennoch sind viele Menschen unfreiwillig aus der digitalen Welt ausgeschlossen. Wie könnte das Internet für alle nutzbar werden?

selbstverständlich antifaschistisch! Aktuelle Informationen zu den Verfahren im Budapest-Komplex - von family & friends Hamburg (de)

Andreas family & friends Hamburg, Birgit family & friends Hamburg

Mit den Prozessen im Budapest-Komplex wird ein Exempel statuiert - nicht nur gegen Einzelne, sondern gegen antifaschistische Praxis insgesamt. Die Behauptung einer kriminellen Vereinigung mit Mordabsichten stellt eine absurde juristische Eskalation des staatlichen Vorgehens gegen Antifaschist*innen dar und steht in keinem Verhältnis zu den verhandelten Vorkommnissen. Die Verfahren in dieser Weise zu verfolgen, lässt vor allem auf ein hohes Ausforschungs- und Einschüchterungsinteresse schließen. Mit dieser Prozesswelle und den Repressionen gegen Freund*innen und Angehörige wird antifaschistisches Engagement massiv kriminalisiert und ein verzerrtes Bild von politischem Widerstand gezeichnet - während gleichzeitig rechte Gewalt europaweit zunimmt und faschistische Parteien erstarken. Wir sehen, dass Angriffe auf Rechtsstaatlichkeit und Zivilgesellschaft immer weiter zunehmen. Die Art und Weise, wie gegen die Antifas im Budapest-Komplex und im Antifa-Ost Verfahren vorgegangen wird ist ein Vorgeschmack darauf, wie politische Opposition in einer autoritären Zukunft behandelt werden könnte. Wir sind alle von der rechtsautoritären Entwicklung, von Faschisierung betroffen. Die Kriminalisierung von Antifas als "terroristische Vereinigung" ist Teil einer (weltweiten) Entdemokratisierung und Zersetzung von Rechtsstaatlichkeit.

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.

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))

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.

4ever punk (en)

DJ Baba Grande

one hour of punk music, encompassing many different styles

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

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.

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.

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

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).

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

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.

Fimi & Nush (de)

Hanni

Fimi&Nush