PTS2025

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

With the current massive user migration from X and Meta to decentralized social media such as Mastodon, the interest in federated communication infrastructures is gaining traction. We have been documenting similar tendencies since 2018 already, analyzing how users in various contexts shift their preferences in terms of secure messaging applications. In the context of a longitudinal study of secure messaging apps users and developers this presentation proposes to analyze several waves of user migrations and suggests an analytical framework to understand the changes in the perception of what’s a “good secure messaging app” with a particular attention to federated architectures and their potential. The “Signal gate” has shown that cryptographic properties of a messaging app per se do not offer a guarantee of security, and many other (sometimes even non-technical) qualities enter the game. We propose to understand digital security as an evolving sociotechnical process of adjusting tools and behaviors and to question the race for an “always more secure” messaging app. We argue that infrastructural choices (centralized vs decentralized vs distributed) and social practices (such as contact discovery) matter.