Blockchain is a topic that has gained notoriety in recent years in relation to its use in cryptocurrencies such as Bitcoin, which has led to an extensive research of its potential applications. Many different fields and businesses have considered adopting it to transform their processes towards a more distributed, decentralized approach. This thesis aims to analyze the application of blockchain systems to Location Base Services (LSBs), in particular to prove the truthfulness of the location of their users. In some cases, such as location-based games, a user's self declared position is not enough, since it could be forged at their own convenience.