Mobility data has become a strategic asset in urban planning, crisis management and smart city operations. However, centralized systems for mobility tracking raise severe privacy concerns (De Montjoye et al., 2013), as they often lack transparency, enforce global data collection and have the ability to directly link individuals to their movements. To address these issues, we introduce LoChain, a decentralized protocol that enables the privacy-preserving collection and processing of mobility data based on blockchain technology. LoChain is designed to be decentralized, minimize data collection, reduce the risk of reidentification while promoting regional autonomy over mobility information.