 Smart grids in cyber-physical systems, CPS, have been developed to improve the safety, reliability, and efficiency of energy production and distribution. To ensure the proper operation of these systems, they must be protected from malicious actors and unauthorized entities. This paper discusses the importance of key management and authentication mechanisms in protecting smart grid systems from attack manipulation and unauthorized access. It also addresses the main intelligent attacks affecting smart grid systems, as well as the main terms of cryptography, key management techniques, authentication methods, and related research challenges. This article was authored by Mohammed S. Abdelzahar, Mustafa M. Fuda, Ahmed Emron, and others.