A Privacy Framework for Charging Connected Electric Vehicles Using Blockchain and Zero Knowledge Proofs

With the increasing interest in connected vehicles along with electrification opportunities, there is an ongoing effort to automate the charging process of electric vehicles (EVs). However, charging EVs takes time and thus in-advance scheduling is needed. This, however, raises privacy concerns since frequent scheduling will expose the charging pattern of the EV to the service providers. Nevertheless, the EV needs to be authenticated which means some information will need to be provided anyway. While there have been many studies to address the problem of privacy-preserving authentication, such solutions will be void if charging payments are made through traditional means. In this paper, we tackle this problem by utilizing distributed applications enabled by Blockchain and smart contracts. We adapt zero-knowledge proofs to Blockchain for enabling privacy-preserving authentication while removing the need for a central authority. The evaluation indicates that the overhead of this process is affordable to enable real-time charging operations for connected EVs.