Review of Privacy Preservation with Blockchain Technology in the Context of Smart Cities

Blockchain technology has credit for empowering smart cities. Due to the generation of huge amounts of data for direct transactions between devices, blockchain technology, by definition, must be used in this type of context. Although, due to the use of large amounts of multidimensional data, exists a risk that users' privacy may be violated. This privacy issue turns out to be of paramount importance, especially with new privacy regulations, like the General Data Protection Regulation (GDPR), that legalizes the requirement to protect the privacy of personal information. This work contributes with a review of the current state of the art in the context of blockchain-based smart cities and how it is managed the privacy-preserving issue.