Guest editorial: Blockchain technologies and applications

Blockchain is a technology that uses community validation to synchronize the content of ledgers replicated by multiple users. Although Blockchain derives its origins from technologies introduced decades ago, recently it has received an astonishing amount of attention in both academic and industry due to its characteristics of decentralization, point-to-point transmission, transparency, traceability, non-tampering, and data security. Both researchers and practitioners have recognized that Blockchain can be used to solve complex technical or socio-economic problems. In recent times, a number of blockchain-based applications have been released in the literature and Blockchain's approaches are used to other cases. For example, as an emerging distributed architecture and computing paradigm, Blockchain technologies have accelerated the development/application of the Internet of Things, Artificial Intelligence, Cloud/Edge Computing, Social Networking, Finance, Insurance, Healthcare, and Supply Chain Management. The popularity and rapid development of Blockchain bring many technical and regulatory challenges for research communities. There is a pressing need to balance between technical and regulatory requirements.