Over the last decade, Internet of Things (IoTs) have brought radical changes to the means and forms of communication for monitoring and control of a large number of applications including Smart Grid (SG). Traditional energy networks have been modernized to SGs to boost the energy industry in the context of efficient and effective power management, performance, real-time control and information flow using two-way communication between utility provides and end-users. However, integrating two-way communication in SG comes at the cost of cyber security vulnerabilities and challenges. In the context of SG, node compromise is a severe security threat due to the fact that a compromised node can significantly impact the operations and security of the SG network. Therefore, in this chapter, Key Management Scheme for Communication Layer in the Smart Grid (KMS-CL-SG) has proposed. In order to achieve a secure end-to-end communication we assign a unique key to each node in the group.