The "Research and Application of Digital Identity Blockchain Technology Based on Legal Documents" led by the First Research Institute of the Ministry of Public Security was officially launched and entered the implementation stage. The project will establish a distributed digital identity architecture based on the "Chang'an Chain". IoT devices, Typical scenarios such as public services and electronic payments will be piloted first. In the field of the Internet of Things, citizens use verifiable digital identity certificates to replace the original admission cards, access control cards and other passes; in the field of public services, citizens use their own digital identity certificates to replace the original various certificates, and dozens of government services can be realized "One certificate for all applications"; in terms of electronic payment, citizens are supported to use distributed digital identities to link multiple bank accounts, so as to realize "one authentication, multi-party processing".