Blockchain is a distributed database technology that connects data blocks in an orderly manner and ensures its tamper ability and forgery by means of cryptography. Generally speaking, blockchain technology can realize the openness, transparency, tamper ability, forgery and traceability of all data information in the system without the endorsement of a third party. As a kind of underlying protocol or technical solution, blockchain can effectively solve the trust problem and realize the free transfer of value. It has a broad prospect in the fields of digital currency, financial assets transaction settlement, digital government affairs, security data services and so on. Topics of interest for submission include, but are not limited to: