  The popularity of Electric Vehicles (EVs) has been rising across the globe in
recent years. Smart grids will be the backbone for EV charging and enable
efficient consumption of electricity by the EVs. With the demand for EVs,
associated cyber threats are also increasing. Users expose their personal
information while charging their EVs, leading to privacy threats. This paper
proposes a user-empowered, privacy-aware authenticated key exchange protocol
for EV charging in smart grid. The proposed protocol is based on the concept of
Decentralized Identifier (DID) and Verifiable Credentials (VCs). The use of
DIDs empowers users by helping them to have complete control over their
identities. The charging station and the user verify that the other party is
legitimate before proceeding with the charging services using VC. Key recovery
is another issue we address in this paper. A method to recover lost keys is
incorporated into the proposed protocol. We present formal security proof and
informal analysis to show that protocol's robustness against several attacks.
We also provide a detailed performance analysis to show that the proposed
protocol is efficient.
