Research And Implementation Of Digital Certificate System Based On Blockchain

With the rapid rise of the Internet economy and online office,traditional industries have begun to move closer to the Internet.Among them,applications such as ecommerce,online payment,and smart government affairs have developed rapidly.At the same time as the transformation,the security problems in these aspects have become increasingly prominent.In order to protect the security of communications in the Internet and achieve reliable information exchange and identity authentication in an untrusted environment,it is necessary to rely on public key infrastructure(PKI)for data encryption and identity authentication operations,but the existing CA system has many shortcomings,such as Single point of failure,vulnerability to attacks and other challenges that make it difficult to trace the contaminated certificate.Moreover,users need to provide necessary identity information for certification when applying for a certificate,but this information lacks the necessary security protection,which makes the information easy to be leaked.In response to the above problems,this article has conducted an in-depth study on the dynamic accumulator,and by constructing the dynamic accumulator in the smart contract,the query efficiency of the data on the chain is improved,and the storage pressure of the blockchain is reduced.This article designs and implements operations such as querying,adding and revoking blockchain certificates.Then,a user identity privacy protection scheme is proposed.Aiming at the problem of identity information leakage in the process of user certificate application,a user identity information privacy protection protocol is designed to realize that users can autonomously control their identity information while protecting the user's identity information privacy.Finally,combined with the proposed algorithm,a decentralized and privacy-protected digital certificate system based on the blockchain is designed and implemented.User certificates are managed and stored on the blockchain to realize the decentralization of digital certificate management and avoid the traditional Problems such as easy failure and network security caused by the centralized issuance of the CA system.Aiming at the problem that the identity information submitted by users in the process of applying for a certificate is easy to be leaked,based on proxy re-encryption technology and IPFS,the reliable sharing of user identity information can be realized on the premise of ensuring user privacy and security.The test results show that the digital certificate system based on the blockchain constructed in this paper can realize the life cycle management of the certificate on the blockchain,guarantee the security of user identity data through proxy re-encryption technology,and achieve the expected requirements of the system design.