Chaos Computer Club - recent events feed

This talk will detail how to integrate external threat intelligence data into an autonomous agentic AI system for proactive cybersecurity. Using real world datasets—including open-source threat feeds, security logs, or OSINT—you will learn how to build a data ingestion pipeline, train models with Python, and deploy agents that autonomously detect and mitigate cyber threats. This case study will provide practical insights into data preprocessing, feature engineering, and the challenges of adversarial conditions. about this event: https://talks.python-summit.ch/sps25/talk/QNWFTD/

Secure communication leveraging the Matrix protocol for UNICC and its partners Licensed to the public under https://creativecommons.org/licenses/by-sa/4.0/ about this event: https://cfp.2025.matrix.org/matrix-conf-2025/talk/WM9WAE/

Being able to read the conversation in a room before you joined is a critical feature for some usecases, but end-to-end encryption makes it tricky to implement. In this technically-focussed talk, we'll cover the challenges behind implementing "history sharing", why previous attempts in this area failed, and how we solved those problems with minimal impact on the security or efficiency of the protocol. The Element Crypto team have been working on [MSC4268](https://github.com/matrix-org/matrix-spec-proposals/pull/4268), aka "Sharing room keys for past messages". We'll talk about why this is difficult from the cryptographic perspective, and discuss the architecture behind the implementation. Licensed to the public under https://creativecommons.org/licenses/by-sa/4.0/ about this event: https://cfp.2025.matrix.org/matrix-conf-2025/talk/VLF9QQ/

In this talk, we will share the newest improvements to MatrixRTC. We'll focus on how the security and encryption architecture has evolved to provide robust, private communications for Matrix users. Additionally, we will show how to integrate Element Call into clients using the Rust or JS-SDK in a matter of minutes. Whether you're building a custom Matrix client or want to know what makes MatrixRTC such a great solution for secure communication, you'll walk away with practical knowledge to bring encrypted calling capabilities to your users and an in-depth understanding about the key distribution for real- time (MatrixRTC) sessions. In this talk, we'll explore the evolving landscape of MatrixRTC, the real-time communication layer of the Matrix protocol, and highlight key advancements. This year we saw a lot of advancements for MatrixRTC. To make it thorugh the spec review process we gathered feedback and added a couple of our own topics that we really wanted to improve. The changes might seem very small but have a very big impact in how good it fits into the matrix eco system. To name one of the highlights: A matrixRTC session can now be dirstirbuted over multiple SFU servers! On top of that a new matrix primitive will be introduced that greatly helps MatrixRTC and is useful in other parts of the ecosystem. With the spec proposals being as polished as never before and the first reviews from SCT members, there is no better time to accelerate the adoption of MatrixRTC-based calls. With Element Call, we went the extra mile to make this adoption as easy as possible. Element Call, being a widget, is available to the broader ecosystem and can be used as a shortcut to make clients compatible with MatrixRTC calls without much development effort. We would like to show how easy it is to implement Element Call into any JS-SDK or Rust SDK backed client (any client supporting the widget API). At the end of the talk, we will have a live demonstration of a call with a client that did not previously support MatrixRTC-based VoIP. Licensed to the public under https://creativecommons.org/licenses/by-sa/4.0/ about this event: https://cfp.2025.matrix.org/matrix-conf-2025/talk/UQVVRV/

The French government has deployed a private Matrix federation for French civil servants called Tchap. Currently this federation has about 300 000 monthly active users and its usage is growing constantly. Today our federation is closed and we would like to be able to connect with other public French Matrix nodes (local authorities for instance), and also other European countries. We should implement measures to ensure that the federation remains resilient against potential attacks, both technical (e.g., DDoS, data interception) and organizational (e.g., unauthorized access, insider threats) : - How can we restrict the servers we wish to communicate with? How can we be sure that we are actually communicating with them? Since TLS can be vulnerable to man-in-the-middle attacks by state actors, we can't rely on it entirely. - How can we trust the identities of users from external deployments that we don’t control? - How can we limit the interactions that external users can have with users from our federation? We spent a lot of time thinking about this and now have a plan that looks legit, and that we are currently implementing. I'm sure you want to know more about it, right? In this talk, we will share the approach we’ve taken to address these challenges and we will present the architecture we designed. Licensed to the public under https://creativecommons.org/licenses/by-sa/4.0/ about this event: https://cfp.2025.matrix.org/matrix-conf-2025/talk/WWAVBQ/

As EU member states (co-)develop sovereign workspace solutions for the public sector, the need for seamless communication between these platforms becomes increasingly important. France, Germany, and the Netherlands are among the countries working on such solutions together, with the goal of facilitating cross-border collaboration and data exchange while maintaining security and sovereignty. In collaboration with our French and Dutch partners, we at ZenDiS are developing a framework to enable communication between our openDesk office and collaboration suite and its international equivalents. Our effort aims to facilitate cross-border information sharing and promote a more integrated European digital landscape. Licensed to the public under https://creativecommons.org/licenses/by-sa/4.0/ about this event: https://cfp.2025.matrix.org/matrix-conf-2025/talk/7SRHXV/

The Invisible Crypto initiative intends to make Matrix easier to use by ensuring that encrypted messaging is secure by default, and the user is not bothered by irrelevant information. In this talk we will give a status update, hopefully explaining why crypto needed to become slightly more visible on the journey towards making it disappear. We'll go into some detail about what we've done (and why some of it makes things a little more noisy) and what we plan to do to really get there. We've been working on the Invisible Crypto initiative for over a year, and arguably things have got worse rather than better: some parts of Matrix crypto are more visible than they were before. We will go into some detail about what we've done so far and why those things temporarily make more noise, but will eventually lead to a peaceful, hassle-free experience of encrypted messaging. Most of the coding has been done in matrix-rust-sdk and the Element clients, but the intention is for these efforts to serve as examples for other implementations. Key goals of the initiative are to ignore "insecure" devices, and treat user identities as trust-on-first-use by default. To make these possible, we have worked on a lot of things that actually make crypto more visible: - Shields for messages from insecure devices - Encouraging device verification - Building a shared language to talk about crypto - Noticing and warning about devices with incomplete crypto information - Warnings about messages whose sender identity is unsure - Letting the user know when an identity changes and we plan to continue with things that mostly make crypto less visible, while also becoming more secure: - Excluding insecure devices - Authenticated backup - Sharing identity updates between devices - Fixing bugs that allow a device's crypto information to be incomplete - Showing identity changes in timelines instead of pop-ups - "Dehydrated" devices so messages received while logged out can be decrypted - Recovery key management Improving crypto-related code is always painstaking, but we hope to convince you that we are making steady progress, and demonstrate how you can help! Licensed to the public under https://creativecommons.org/licenses/by-sa/4.0/ about this event: https://cfp.2025.matrix.org/matrix-conf-2025/talk/BT8WR9/

In this talk, we trace the journey of evolving Rocket.Chat from a standalone collaboration server into a full-fledged Matrix home-server — all built in TypeScript. We’ll dive into the architecture decisions, the incremental features (federation, room state sync, identity translation, event routing, crypto, and bridging), and the real challenges of combining two paradigms (Rocket.Chat’s internal model + the Matrix spec) in one codebase. You’ll hear about lessons learned: when to build vs reuse, how we manage consistency under asynchronous federation, strategies for performance and rate limits, and how we maintain feature parity while gradually merging homeserver responsibilities. Whether you’re running a chat platform, building a new homeserver, or simply interested in bridging monolithic systems with Matrix, this session will provide deep technical insight and lessons you can bring back to your project. Licensed to the public under https://creativecommons.org/licenses/by-sa/4.0/ about this event: https://cfp.2025.matrix.org/matrix-conf-2025/talk/J7YNGR/

Docling is an open-source Python package that simplifies document processing by parsing diverse formats — including advanced PDF understanding — and integrating seamlessly with the generative AI ecosystem. It supports a wide range of input types such as PDFs, DOCX, XLSX, HTML, and images, offering rich parsing capabilities including reading order, table structure, code, and formulas. Docling provides a unified and expressive DoclingDocument format, enabling easy export to Markdown, HTML, and lossless JSON. It offers plug-and-play integrations with popular frameworks like LangChain, LlamaIndex, Crew AI, and Haystack, along with strong local execution support for sensitive data and air-gapped environments. As a Python package, Docling is pip-installable and comes with a clean, intuitive API for both programmatic and CLI-based workflows, making it easy to embed into any data pipeline or AI stack. Its modular design also supports extension and customization for enterprise use cases. We also introduce SmolDocling, an ultra-compact 256M parameter vision-language model for end-to-end document conversion. SmolDocling generates a novel markup format called DocTags that captures the full content, structure, and spatial layout of a page, and offers accurate reproduction of document features such as tables, equations, charts, and code across a wide variety of formats — all while matching the performance of models up to 27× larger. about this event: https://talks.python-summit.ch/sps25/talk/QJLGCZ/

Traditionally, marketing campaign analysis relies on simple metrics like the number of purchases made after a contact, or conversions following a promotion. While these numbers tell us what happened, they don’t reveal why it happened or if the campaign truly made a difference. Such analysis can’t distinguish between customers who would have acted anyway and those who were genuinely influenced by the campaign. The key question is: did the campaign actually cause the desired effect? In this practical and beginner-friendly session, we’ll explore how Causal Machine Learning provides the missing piece in campaign evaluation and targeting. Starting from real-world scenarios, we’ll dive into: Why causality matters more than correlation when evaluating ad performance. How to estimate the true impact of a campaign using uplift modeling and treatment effect estimation in just a few lines of code. How to target users who are not just likely to interact with ads, but whose behavior can be influenced by the campaign (for example, to reduce churn or boost engagement). The session will be hands-on with Python, with clear examples drawn from marketing applications. about this event: https://talks.python-summit.ch/sps25/talk/MNJ98W/

Are we OIDC yet ? YES ! We are ! OpenID Connect evolved as the one and only identity standard in the modern web. With MSC3861, the [matrix] ecosystem is finally moving to OIDC as the authentication standard amongst clients and homeservers. Out of curiosity, I started implementing a native OIDC implementation from scratch : no OAuth 2.0 library, no Ruma ; just the [matrix] Dart SDK, an HTTP client and the MSC in front of me. This talk will be about the lessons learned. Licensed to the public under https://creativecommons.org/licenses/by-sa/4.0/ about this event: https://cfp.2025.matrix.org/matrix-conf-2025/talk/XLV7PZ/

The federation protocol is how Matrix homeservers communicate between each other. In private federations this isn't particularly challenging as the network is trusted but in the public federation this isn't true. This talk dives into what protocol improvements are in the works to make the public federation more secure against Byzantine actors, particularly against "state resets": an unintended rollback of room state. We'll explore why this problem is hard, what some of the failure modes are, and how we are working on addressing them. The federation protocol, in particular state resolution, is one of the most important parts of Matrix. In the current algorithm, the output from the algorithm can be counter-intuitive, and multiple people have tried to explain how it works (including a talk from me at FOSDEM this year!) with varying degrees of success. This behaviour sometimes rears its ugly head when your room state has rolled back to an earlier point in time for no good reason: a "state reset". Fixing these issues is hard, partly because the current algorithm is so tricky - so over the course of 2025 we’ve been working on improving and (eventually) simplifying it. Along the way, we've developed tooling to help us observe and replay room state in the form of TARDIS: Time Agnostic Room DAG Inspection Service. This tool has been critical for us to produce minimal working examples of state resets and to experiment with algorithmic changes to fix the underlying issues. We'll explore some of these scenarios in TARDIS during the talk. Licensed to the public under https://creativecommons.org/licenses/by-sa/4.0/ about this event: https://cfp.2025.matrix.org/matrix-conf-2025/talk/YK9F38/

In this talk we will provide insights on the new Element Server Suite (ESS) editions which provide an Element-supported way to deploy Matrix stacks. ESS is available in three editions - [ESS Community](https://github.com/element-hq/ess-helm) - the free Matrix distribution from Element for small-/mid-scale, non-commercial community use cases - [ESS Pro](https://element.io/server-suite) - the commercial Matrix distribution from Element for professional use - [ESS TI-M](https://element.io/server-suite/ti-messenger) - a special version of ESS Pro focused on the requirements of TI-Messenger Pro and ePA We will dive deep into each edition, explain how they're meant to be used, shed light on the components they include and discuss which use cases they are tailored to. Licensed to the public under https://creativecommons.org/licenses/by-sa/4.0/ about this event: https://cfp.2025.matrix.org/matrix-conf-2025/talk/MHZQVK/

I Agents are the next big thing everyone has been talking about. They are expected to revolutionize various industries by automating routine tasks, mission critical business workflows, enhancing productivity, and enabling humans to focus on creative and strategic work. Of course, you can apply them to your everyday coding tasks as well. In this talk we’ll go over what those agents can bring to the table of coding world, and why they can deliver the promise of coding smarter that the current generation of coding assistants can’t. We will then dive right into a quick live coding session where I’ll show what such agents can do in real life and how you can start using them to enhance your everyday life already right after the talk. And we’ll finish off with some remarks on what the future of programming might look like in the near future as those agents get included into your everyday life. about this event: https://talks.python-summit.ch/sps25/talk/NTGKGW/

Matrix was built to become the open communication of the web and serve everyone. But, as the Internet and email did, its network effect started with governments. Today, and as proven by the audience in the room, most European governments and several others are either using it or looking at implementing it for their communications. This talk will tell the story of how we got there and why. Licensed to the public under https://creativecommons.org/licenses/by-sa/4.0/ about this event: https://cfp.2025.matrix.org/matrix-conf-2025/talk/CAUAHD/

Demokratis.ch is a non-profit project working to modernise the consultation procedure—a key democratic process that allows Swiss citizens to provide feedback on proposed laws and amendments. Today, the process is slow and cumbersome for everyone involved: it requires studying lengthy PDFs, writing formal letters, and even synthesising legal arguments by copy-pasting into Excel. There’s a huge opportunity to streamline this process and make this democratic tool more accessible and inclusive. In this talk, I’ll share how we’re tackling this challenge with machine learning: building data processing pipelines, extracting features from endless PDFs, embedding and classifying text, designing and evaluating models—and ultimately deploying them in production. Because the data comes from the federal administration and 26 different cantons, it’s often heterogeneous and in varying formats. Data quality, in general, presents many challenges for both training and evaluation. Spoiler: PDF is a pretty terrible format for machines … Our approach is practical and pragmatic, and our code is open source, so you’re welcome to explore our solutions or even contribute yourself! about this event: https://talks.python-summit.ch/sps25/talk/EWUJKH/

Element X is coming to web and desktop! What does that mean? We’re going to make the apps simple, familiar, reliable and fast! Come learn more about the vision we have put together and all the progress we have made so far! The talk will cover: * The qualities/goals we are aiming for in EWX * The high level plan to achieve this including: * Our product and design strategy * The phased plan for delivery * The key technologies that will enable the transformation * An update on progress and next steps Licensed to the public under https://creativecommons.org/licenses/by-sa/4.0/ about this event: https://cfp.2025.matrix.org/matrix-conf-2025/talk/SJFXGH/

Access control is the core of any system's security, but usually provided by a single, centralized server. However, access control in a Matrix room is decentralized: every participating server *independently* decides *who* is authorized to send and receive *which* events, without consulting any other server. To the surprise of many, these decisions are still *eventually* consistent even if all but one server is malicious, but seeing *why* requires a new way of thinking about access control. I will explain the necessary design patterns from decentralized systems science, and show how they can be weaved together for a practical explanation of what Matrix is, and why Matrix can reach its astonishing levels of security and resilience. In this talk, I provide a primer on **design patterns from decentralized systems theory**, and explain what they mean for the current and future design of Matrix in practice. I will start with **concurrency as the root of all problems in decentralized systems**, and how network partitions and arbitrarily malicious servers stand in the way of consistency. Based on these problems, I will explain **conflict-free replicated data types** (CRDTs) and hash linking as the solution to still make a Matrix room eventually converge at all benevolent servers. Finally, I will show you my **access control to the best of knowledge and belief** way of thinking about eventually consistent access control in Matrix – you need to think in **two authorization decisions per event**, of which one is final on receiving the event, while the other one may ever be changing on receiving new concurrent events. Licensed to the public under https://creativecommons.org/licenses/by-sa/4.0/ about this event: https://cfp.2025.matrix.org/matrix-conf-2025/talk/X3KDAQ/

Presentation of the Luxembourg efforts to establish a sovereign instant messaging ecosystem for the public and private sector for Luxembourg. More details to follow. Licensed to the public under https://creativecommons.org/licenses/by-sa/4.0/ about this event: https://cfp.2025.matrix.org/matrix-conf-2025/talk/GEEKMY/

A welcome message and useful information from the organisers. You will also find useful information on our [website](https://www.python-summit.ch/). Or feel free to ask any member of staff if you have a question. about this event: https://talks.python-summit.ch/sps25/talk/D7KQWT/

In this talk we will cover - what is the Governing Board about - how does it fit into the Foundation - reviewing the last 12 months and outputs - showing some of the different processes like establishing Working Groups, what Committees are, interactions with the Foundation - what next - how to get involved in open governance - take some questions Licensed to the public under https://creativecommons.org/licenses/by-sa/4.0/ about this event: https://cfp.2025.matrix.org/matrix-conf-2025/talk/XDT3BL/

A whistle stop tour of Element’s progress over the last year! Highlights include Element Server Suite Community, the latest on Element X, Spaces, Threads and Element Call. There’s also Element Server Suite Pro, Synapse Pro and the launch of Element Pro; the Element app specifically for the workplace! Licensed to the public under https://creativecommons.org/licenses/by-sa/4.0/ about this event: https://cfp.2025.matrix.org/matrix-conf-2025/talk/WEASKJ/

A thank you from the organisers. We hope you enjoyed your day! about this event: https://talks.python-summit.ch/sps25/talk/AZGSCP/

Our Lightning Talks are open to everyone 😊 about this event: https://talks.python-summit.ch/sps25/talk/EP7BNX/

Over the years, the lack of an array data type in Python has resulted in the creation of numerous array libraries, each specializing in unique niches but still having some interoperability between each other. NumPy has become the de facto array library of Python, and the other array libraries try to keep their API close to that of NumPy. However, this often becomes infeasible, and the libraries deviate out of necessity. To make Python's array libraries shake hands with each other without any inconsistencies, the Consortium for Python Data API Standards has formalised an Array API standard for libraries offering array creation and manipulation operations. The Array API standard allows users to write and use the same code for arrays belonging to any of the standard-conforming libraries. Through this talk, we will explore the need for such standardisation and discuss its salient features in detail. We will primarily delve into the example of using this standard to make specific parts of European Space Agency's Euclid space mission's code GPU and autodiff compatible. Besides cosmology, we will also take a look at a few other examples, mostly sourced from my experience working with and on several Python array libraries for scientific computing. Ultimately, the audience can expect to leave the room with the knowledge of both, the software engineering and the research side of the array API standard. about this event: https://talks.python-summit.ch/sps25/talk/B7GRMJ/

Open Source has never been easy, but doing Open Source in the Matrix ecosystem poses a unique set of challenges. Add the pressure of sustaining a company on top of that, and you quickly find yourself in uncharted, and often uncomfortable, territory. This talk reflects on the reality of maintaining open source projects in the Matrix universe, especially from the perspective of a business. It dives into the tension between openness and exploitation, when others take your work without contributing anything in return, undermining sustainability and motivation. Through real-world experiences and hard-learned lessons, this session will outline the structural and cultural issues that make it harder for corporate contributors to survive in the ecosystem. We'll look at why fair contribution is hard to enforce, how "Trittbrettfahrer" (free riders) hurt long-term progress, and what we as a community - maintainers, companies, and individuals - can do to shift the dynamic. Whether it's licensing strategies, community governance, or pushing for upstream responsibility, this talk will explore the imperfect but necessary mechanisms we need to keep Matrix open, but not exploitable. The goal isn't to complain, but to open up a grounded and honest discussion about sustainability, fairness, and the future of open collaboration in Matrix. Licensed to the public under https://creativecommons.org/licenses/by-sa/4.0/ about this event: https://cfp.2025.matrix.org/matrix-conf-2025/talk/QG8QQU/

It has been known since the 70s that developers tend to give very optimistic estimations. We prefer to have exact numbers, even if that means they are wrong most of the time. In research, developers admitted that they believe their managers will see them as less competent if they provide estimates with huge margins. But mathematically speaking providing a wider min-max interval means you will be right more often. So, maybe it isn’t really accuracy that businesses and people are looking for. Maybe estimates are needed for the sole purpose of risk aversion. Risk can be measured in other ways. Maybe it is time we stop estimating tasks left and right and instead start managing the project’s risk and customer’s expectations. about this event: https://talks.python-summit.ch/sps25/talk/7EKTCB/

See a demo of E2EE encrypted DMs in Bluesky powered by Matrix. We will highlight the simple user experience and other advantages of this approach to adding E2EE to Bluesky. By reusing Matrix for E2EE DMs in Bluesky, we not only offer a trusted and tested open source encryption stack but also allow users to later expand their usage beyond chat to other Matrix features such as E2EE voice, video and more. Alternate approaches to build E2EE from scratch in Bluesky will take many years to achieve feature parity with Matrix. Moreover the federated Matrix architecture can allow Bluesky users a BYOMA (Bring Your Own Matrix Account) option, that stands as a unique advantage, not available from any other social media. Matrix enthusiasts should be excited, as the adoption of this approach for E2EE DMs in Bluesky can significantly expand the Matrix user base, and draw in many more users to experience the richness of the Matrix ecosystem. Licensed to the public under https://creativecommons.org/licenses/by-sa/4.0/ about this event: https://cfp.2025.matrix.org/matrix-conf-2025/talk/AVAL3A/