Storage Optimization for Certificates in Blockchain Based PKI System

In recent years, many researches on decentralized PKI (Public Key Infrastructure) by using block technology have emerged to prevent problems faced by tradition PKI, such as single point of failure. Certificates are recorded into the decentralized blockchain in many of the researches. With the increased number of certificates, the blockchain based PKI system will occupy a considerable amount of storage space. In this paper, the framework of blockchain based PKI system is introduced, and optimizations for certificate storage are provided. The certificates have expiry dates, and the optimization based on the invalid certificates is proposed. In many applications and scenarios, the target certificates are explicit, and then the optimization based on the target certificates is proposed. These optimization methods could improve the storage efficiency of specific nodes in blockchain based PKI system.