Research on Application of Blockchain in PKI Security

The design idea of emphasizing application and neglecting defense leads to the lack of endogenous security attributes at the beginning of the design of transmission control protocol/Internet protocol (TCP/IP) architecture. Public key infrastructure (PKI), as an authoritative security governance framework to realize the authenticity, integrity, confidentiality and non-repudiation of communication between different entities on the Internet, has attracted much attention since it was proposed, which has also become the focus of researchers in recent years because of single point of failure and single trust and other security threats caused by the centralized mechanism of PKI. With the gradual application of blockchain technology in the field of information security, it has become a research direction and focus to use the characteristics of decentralization, distributed ledger, tamper-proof, openness and transparency of blockchain to solve various security problems arising in the native PKI and its evolution. According to the application and development of PKI and blockchain, the methods to solve PKI security are divided into the solutions based on Web of trust (WoT) technology and certificate transparency (CT) mechanism, which do not rely on blockchain, the centralized PKI solutions integrated with blockchain technology, which retain the core function of certificate authority (CA), and the decentralized PKI schemes based on blockchain, which completely replace the CA function with blockchain. Firstly, the security status of the original PKI is introduced, and the methods using WoT technology and CT mechanism to transform the security of the original PKI are discussed respectively. Then, the design ideas of centralized PKI integrated with blockchain technology and decentralized PKI based on blockchain are analyzed. Some typical application scenarios are selected to analyze their implementation methods and application characteristics. Finally, the application research of blockchain in PKI security is prospected.