Abstract
Verifying physical presence in digital systems is essential for secure authentication, authorization, and accountability. Proof-of-Location (PoL) systems address this need by enabling verifiable, tamper-resistant claims of location and time, particularly in adversarial environments where traditional localization methods such as GPS fall short. While recent efforts have explored decentralized PoL architectures, existing systems often lack a unified model that integrates spatio-temporal synchronization, distributed consensus, and cryptographic attestation. In this paper, we formalize the architectural foundations of decentralized PoL systems by introducing a composable model based on fault-tolerant witnessing zones. We define core components for synchronization and collective attestation, integrating primitives such as distributed digital signatures, distance bounding protocols, and consensus mechanisms. We contextualize the model across diverse application domains that necessitate digital trust-such as civic processes, content authentication, infrastructure auditing, and supply chain tracking-and argue for a shared, interoperable decentralized PoL infrastructure. To validate our design, we implement and emulate a reference protocol instance, analysing scalability, synchronization behaviour, and timing misalignment under varied conditions. We also outline its security model and discuss limitations and future directions in privacy, interoperability, and real-world deployment. Our contributions lay a formal and practical foundation for scalable, secure, and general-purpose decentralized PoL systems.