  The increased use of smart Electric Vehicles (EVs) and Plug-in Electric
Vehicles (PEV) opened a new area of research and development. The number of EV
charging sites has considerably increased in residential as well as in public
areas. Within these EV charging sites, various entities need to communicate in
a secure and efficient way. The Open Charge Point Protocol (OCPP) offers a way
to coordinate this communication and is already being used in many
implementations. However, only the latest OCPP 2.0 version of the protocol
includes certain security features. In this article, we present the entities
that take part in an OCPP-based smart charging scenario, we identify security
issues and threats and present solutions that have been proposed by scholars.We
identify open security issues for OCPP and propose future research directions
for the security enhancement of the protocol.
