Smart grid technology, a reasonable move in modern power system, assures coveted resiliency, consistency, and the utmost efficiency of the entire grid system utilizing the cyber resources via extensive communication between the subordinate bodies. But, like other cyber communication process, the smart grid technology is now in the security concern because of the modern eavesdropping techniques. To keep the system safe and secure from the probable vulnerability, several encryption algorithms have already been developed to ascertain secure data transmission. But, the processing time of these traditional algorithms is comparatively higher and this drawback certainly endangers the system security. In this paper, the authors have introduced a short run time based secure encryption algorithm that can literally fulfil the security requirements in microgrid systems. In particular, this proposed algorithm is designed in two manners: Key-based and Key-less approaches with the elaborate delineation so that one can easily compare the security parameters, process runtime, and consistency with the current encryption algorithms. Finally, to vindicate the legitimacy of the proposed algorithm, all the results and issues have been verified in the simulation platform such as Matlab/Simulink.