"Blockchain-based certificate system" is another national patent recently obtained by CPChain. This invention is a distributed identity and digital certificate system based on blockchain.

We use public-key encryption technology to realize the distributed generation of unique IDs of users, and can associate different digital certificates. At the same time, blockchain technology is used to realize operations such as revocation and verification of digital certificates. From the perspective of certificate use, the participants of the system include the issuer, the holder, and the verifier. In different applications, the identities of these three parties can be transformed into each other. In the real world, the entities of these three may be people, enterprises, organizations, or IoT devices.

The currently widely used certificate system in the world is centered on CA (certificate authority). This system has the following problems: the type of certificate is single; the entry threshold of CA is very high; the revocation of the certificate is inconvenient.

Our invention uses blockchain and distributed storage technologies to design a new digital identity and certificate system. All users can register as an issuer (corresponding to the CA institution in the traditional system) through the blockchain network and freely define the types of certificates that can be issued. The issuer can revoke the certificate in real time through the blockchain network, and the verifier can also verify the certificate through the blockchain. In this way, the problems encountered by the traditional CA system can be solved.

In summary, the features of this program are as follows:

• The use of blockchain technology to realize a fully distributed certificate system and lower the barriers to participation;
• With more flexible certificate definitions, the application fields of digital certificates have been greatly expanded;
• The certificate revocation mechanism is realized through the smart contract, and the certificate status can be updated in real time.

In the future, this solution will be used to build a certificate system for the CPChain ecology and is committed to connecting individuals, organizations, enterprises, IoT devices, and other entities to the CPChain manner in a decentralized and trustworthy manner, providing trust guarantee for CPChain IoT ecosystem.