An Alternative to Certi fcate Authorities using Blockchain based Decentralized PKI

Abstract

A digital certi cate is an electronic document which can be used to prove the own- ership of a public key, which is a crucial aspect in web communication. These digital certi cates are issued by a central governing body named Certi cate Au- thorities. Activities of these certi cation authorities are not transparent and not audited as well. The problem with certi cation authorities is that the internet community need to trust these certi cation authorities completely and currently we have placed immense trust in them. Due to the importance of the certi cation authorities they are tempting targets of criminals. There are many real-life examples for cer- ti cation authorities being hacked or misbehaving. If the certi cation authority is compromised, it is possible to create fake digital certi cates which can be used for malicious activities. We have identi ed the reason for this issue is the fact that certi cation au- thorities can be considered as a single point of failure in public key infrastructure. Hence in this project we propose to eliminate this central gure and try to nd out whether it is possible to decentralize the functionalities of a certi cation au- thorities by incorporating the blockchain technology. In this project, we have followed an experimental research approach. Our prototype implementation \TLSChain" is based on Ethereum blockchain network and integrated with novel on-chain domain veri cation. The test cases carried out revealed that the blockchain technology is a well-suited platform to build a Public Key Infrastructure and possible to eliminate Certi cate Authorities. After evaluating the monetary side of \TLSChain", it was evident the design should address the scalability aspect due to the volatile nature of the cypto currency market.