Cryptography emerged from a fundamental recognition: secure communication cannot rely on trusted intermediaries or centralized authorities. This skepticism toward concentrated power finds parallel expression in the Austrian school of economics, particularly Friedrich Hayek's critique of government monetary monopolies and advocacy for competing currencies. At the intersection of cryptographic distrust and economic liberalism, Bitcoin introduced blockchain technology as a foundation for competing digital currencies secured by cryptography rather than central authorities, enabling decentralized consensus where trust emerges paradoxically from mutual distrust among network participants.

This thesis advances distributed ledger theory through two contributions. First, we address the digitalization of local currencies through four blockchain-based constructions: Base-Local establishes a foundational framework; Geo-Limited enforces geographical constraints via distance-bounding protocols; Geo-Demurrage introduces geographical demurrage where currency value decreases with distance; and Uni-Local demonstrates universal scalability while maintaining local spending incentives.

Second, we introduce Proof of Behavior (PoB), a consensus mechanism replacing energy-intensive computations with verifiable human actions. We resolve the dichotomy between decentralization and behavioral verification through a framework integrating Verifiable Delay Functions for sequential mining. The architecture includes a fuel-and-bounty transaction system ensuring size-neutral fees, temporal demurrage balancing money creation, and a checkpoint mechanism leveraging pBFT consensus with BLS signature aggregation to provide deterministic finality and enable storage pruning. We establish security guarantees through correspondence with the Bitcoin Backbone Protocol while identifying and mitigating PoB-specific attacks including selfish mining and concurrent sibling blocks. The prototype EcoMobiCoin validates feasibility by rewarding ecological mobility.

These contributions demonstrate that blockchain technology can serve socially aligned objectives while maintaining rigorous security and decentralization principles essential to trustless systems.

The jury is composed of the following members:

• Ms. Maria Potop-Butucaru, Professor, Sorbonne Université, rapporteuse
• Mr. Quentin Bramas, Associate Professor, HDR, Université de Strasbourg, rapporteur
• Mr. Gérard Chalhoub, Professor, Université Clermont Auvergne, examinateur
• Mr. Romaric Ludinard, Associate Professor, IMT Atlantique, examinateur
• Mr. Pascal Lafourcade, Professor, Université Clermont Auvergne, directeur de thèse
• Ms. Ariane Tichit, Associate Professor, Université Clermont Auvergne, co-encadrante de thèse.

For more information on me and the publications : https://www.fredericahayek.com/about-me#publications