Geo-infrastructures of Sovereignty: Technologies, Cultures, and Politics of Secure Messaging in Switzerland

This dissertation develops a geo-infrastructural approach to digital sovereignty that bridges Science and Technology Studies, Internet Governance studies, and approaches from Critical Geopolitics. Arguing that sovereignty is an emergent process produced through the alignment of material architectures, institutional practices and cultural imaginaries, the study follows the inscription, translation and uptake of political struggles into technical form. Empirically, it is anchored in a multi-sited case study of the Swiss secure-messaging platform Threema, combining systematic document analysis, semi-structured interviews with developers, institutional adopters and users, and technical artifact analysis. The thesis makes three interlocking contributions. First, it advances a conceptual toolkit that foregrounds social practices, sociotechnical imaginaries, and micro-interactions with infrastructure as central loci of geopolitical competition. Second, through the Threema case it shows how a small, private platform can be enrolled into public practice to produce a localized form of infrastructural nationalism. Design choices become performative claims about jurisdiction, identity and trust when amplified by institutional endorsement. Third, it offers policy-relevant insights for European digital sovereignty: procurement as strategic lever, the need for technical literacy in regulation, and the limits and opportunities of scaling privacy-centric alternatives in the face of network effects. The dissertation concludes that durable, democratic digital sovereignties require attention to the mundane, technical and cultural work that makes infrastructures legible and governable.