Laser Beams & Light Streams: Letting Hackers Go Pew Pew, Building Affordable Light-Based Hardware Security Tooling (39c3)

Stored memory in hardware has had a long history of being influenced by light, by design. For instance, as memory is represented by the series of transistors, and their physical state represents 1's and 0's, original EPROM memory could be erased via the utilization of UV light, in preparation for flashing new memory. Naturally, whilst useful, this has proven to be an avenue of opportunity to be leveraged by attackers, allowing them to selectively influence memory via a host of optical/light-based techniques. As chips became more advanced, the usage of opaque resin was used as...

Verschlüsselung brechen durch physischen Zugriff - Smartphone Beschlagnahme durch Polizei (39c3)

Eine zwar profane Methode der Überwachung, die Polizeibehörden in Deutschland jedoch hunderttausendfach anwenden, ist das Auslesen von Daten beschlagnahmter Smartphones und Computer. Dazu nutzt die Polizei Sicherheitslücken der Geräte mithilfe forensischer Software von Herstellern wie Cellebrite oder Magnet aus. Die Verfassungsmäßigkeit der Rechtsgrundlagen ist zweifelhaft. Im Vortrag werden anhand aktueller Fälle technische und juristische Hintergründe erörtert. Staatstrojaner, Chat-Kontrolle, Wanzen. Die Mittel staatlicher Überwachung sind vielfältig und teilweise technisch sehr komplex. Dabei ist es leicht, den Überblick zu verlieren. Ein relativ profanes Mittel, das Polizeibehörden in Deutschland hunderttausendfach anwenden, ist die Beschlagnahme von Smartphones und Laptops...

Infrastructure Review (39c3)

Infrastructure teams present what they did for this years congress and why they did it that way. 39c3 is a big challenge to run, install power, network connectivity and other services in a short time and tear down everything even faster. This is a behind the scenes of the event infrastructure, what worked well and what might not have worked as expected. Licensed to the public under http://creativecommons.org/licenses/by/4.0 about this event: https://events.ccc.de/congress/2025/hub/event/detail/infrastructure-review
Video:39c3-1806-eng-Infrastructure_Review.mp4

39C3: Power Off zur Abreise!

Liebe Wesen und Teilnehmende,

das Ende ist nahe! Tage voller Begegnungen, Neugier, Lötzinn, Diskurs, Musik, Code und Chaos liegen hinter uns. Danke, dass ihr diesen Congress mit Leben gefüllt habt. Ihr habt ihn zu dem gemacht, was er ist.

So sehr wir uns wünschen, dass der Congress ewig weiterläuft, kommt nun der Moment des Zusammenpackens, Durchatmens und Abschiednehmens.

Nach dem Closing beginnen die Assemblies damit, ihre Räume wieder zu leeren. Bitte nehmt euch die Zeit, ordentlich und achtsam abzubauen. Räumt möglichst schnell eure Tische frei, damit das Möbelhaus Tische und Stühle abtransportieren kann und Netzwerk und Strom abgebaut werden können. Die Hardware für...

Are We Ready to Be Governed by Artificial Intelligence?

Artificial Intelligence (AI) overlords are a common trope in science-fiction dystopias, but the reality looks much more prosaic. The technologies of artificial intelligence are already pervading many aspects of democratic government, affecting our lives in ways both large and small. This has occurred largely without our notice or consent. The result is a government incrementally transformed by AI rather than the singular technological overlord of the big screen.

Let us begin with the executive branch. One of the most important functions of this branch of government is to administer the law, including the human services on which so many Americans rely....

BE Modded: Exploring and hacking the Vital Bracelet ecosystem (39c3)

The Vital Bracelet series is an ecosystem of interactive fitness toys, content on memory chips, and apps that talk via NFC. In this talk, we'll explore the hardware and software of the series, from its obscure CPU architecture, to how it interacts with the outside world, from dumping OTP ROMs and breaking security, to making custom firmware. The Vital Bracelet series, active from 2021 to 2024, was a line of toys that revolved around a number of fitness bracelets that encouraged exercise by raising characters from the Digimon series, and expanding into tokusatsu and popular...

Rowhammer in the Wild: Large-Scale Insights from FlippyR.AM (39c3)

Last year at 38c3, we gave a talk titled "Ten Years of Rowhammer: A Retrospect (and Path to the Future)." In this talk, we summarized 10 years of Rowhammer research and highlighted gaps in our understanding. For instance, although nearly all DRAM generations from DDR3 to DDR5 are vulnerable to the Rowhammer effect, we still do not know its real-world prevalence. For that reason, we invited everyone at 38c3 last year to participate in our large-scale Rowhammer prevalence study. In this year's talk, we will first provide an update on Rowhammer research and present our results from that...

Learning from South Korean Telco Breaches (39c3)

2025 was a bad year for South Korean mobile network operators. All three operators (SK Telecom, KT, LG U+) were affected by breach in some part of their respective network: HSS of SK Telecom, femtocells of KT. Meanwhile, handling of the breach by each operators and post-mortem analysis of each breaches have stark differences. The technical details and implemented mitigations are often buried under the vague terms, and occasionally got lost in translation to English. In this talk, I will cover the technical aspects of SK Telecom and KT's breach, and how the operators...

Race conditions, transactions and free parking (39c3)

ORM's and/or developers don't understand databases, transactions, or concurrency. After the [Air France-KLM dataleak](https://media.ccc.de/v/37c3-lightningtalks-58027-air-france-klm-6-char-short-code) I kept repeating this was not a real hack, and confessed I always wanted to hack a system based on triggering race conditions because the lack of proper transactions. This was way easier than expected. In this talk I will show how just adding `$ seq 0 9 | xargs -I@ -P10 ..` can break some systems, and how to write safe database transactions that prevent abuse. In this talk I will explain what race conditions are. Many examples of how and why...

The Modular Workshop – The Tunegirl und Rob StrobE (39c3)

Hallo CCC Community, wir präsentieren euch The Tunegirl und Rob StrobE, beide sind mit Veröffentlichungen auf dem Assassins Soldier Label beheimatet und blicken auf eine gemeinsame Liebe für Detroit Techno. Die Idee zum gemeinsamen Workshop für euch entstand natürlich auf dem Dancefloor und The Tunegirl hat die Cases gepackt und nach Hamburg gebracht. Während The Tunegirl den praktischen Teil verantwortet und die Kabel steckt, wird euch Rob durch die Kabel führen und einen Einblick in die Welt der Module und Drummachines geben. Unterstützt wird das ganze von einer Kamera, damit ihr nah am Geschehen dabei sein...