PTS2025

Holger Krekel

Holger is a long-time FOSS contributor. He is co-creator of the python testing tool "pytest", the PyPy project, and since about 10 years engaged in decentralized messaging research and development.
He is one of the co-creators of the Autocrypt and SecureJoin protocols, as well as one of the maintainers of the "Chatmail" project which explores new and more secure ways to run secure e-mail server networking.

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Sessions

07-02
14:00
35min
Usable end-to-end security with Delta Chat and Chatmail
Holger Krekel

Over the years, Delta Chat has matured to be an easy-to-use, secure,
and even fast decentralized FOSS messenger app for all platforms.
In this talk we discuss two key security architectures:

  • Autocrypt and SecureJoin key distribution protocols for achieving
    automatic end-to-end encrypted messaging safe against MITM attacks, and

  • the open-signup Chatmail server network which successfully uses strict
    cryptographic interoperability contraints (DKIM, OpenPGP, TLS)
    instead of IP-reputation and spam classification methods.

We also highlight the six independent security audits and analysis conducted so far.

Secured Messaging
Amphitheater 122
07-03
09:30
180min
Dive into Delta Chat, Chatmail, webxdc apps and P2P realtime
Holger Krekel, Ksenia Ermoshina, missytake

The Delta Chat decentralized instant messaging project has over the years evolved a rich ecosystem of distinct project areas, from instant onboarding with a versatile cross-platform messenger, over using chat-shared web apps with integrated Peer-to-Peer realtime messaging to participating with own Chatmail servers in the world-wide e-mail server network.

First, we onboard all participants on different Chatmail servers and get into a joint chat group and play around with the many features, answer and discuss questions and maybe play some games.

Second, we offer participants hands-on sessions:

  • setting up a chatmail server

  • writing a webxdc app

  • writing a chat bot

Secured Messaging
Room LW109