Blockchain projects ecosystem: A review of current technical and legal challenges

Blockchain is a decentralized transaction and data management technology developed first for Bitcoin cryptocurrency. The interest in Blockchain technology has been increasing since the idea was presented in 2008. The reasons for all the interest around Blockchain comes from its decentralized nature, while providing security, anonymity and data integrity. All these features without any third-party organization in control of the transactions, therefore creating interesting research areas. The Blockchain is a versatile technology, which can be implemented in a vast list of industries and maybe change completely the way we approach some of their use cases. In this paper, we will present some of the most relevant and recent Blockchain projects, classifying them by their main purpose or value proposition. Additionally, we describe the main technical and legal challenges, which may prevent this technology from a more rapid and wider use.This work has been supported by FCT - Fundação para a Ciência e Tecnologia, within the Project Scope: UID/CEC/00319/2019