Network-on-Chip (NoC) is responsible for managing communication in modern SoCs. The ubiquity of NoC and its distributed nature across the chip has made it a focal point of attacks. Spoofing attacks by impersonating the nodes in SoC can lead to unauthorized information access and can also be employed to launch denial of service attacks. Modern software tends to use more parallelism among multiple cores, increasing multicast communication among cores to exchange cache coherence messages. Traditional multicast authentication solutions are not effective due to the resource-constrained nature of NoC-based SoCs. In this paper, we propose a lightweight multicast authentication mechanism. Experimental results demonstrate the effectiveness of our approach with required security while incurring minor area and performance overhead.