The growing and widespread presence of Internet of Things (IoT) has made the lives of all comfortable and handy, but poses various challenges, like efficiency, security, and high energy drain, threatening smart IoT-based applications. Small applications rely on Unicast communication. In a group-oriented communication, multicast is better as transmission takes place using fewer resources. Therefore, many IoT applications rely on multicast transmission. To handle sensitive applications, the multicast traffic requires an actuator control. Securing multicast traffic by itself is cumbersome, as it expects an efficient and flexible Group Key Establishment (GKE) protocol. The paper proposes a three-tier model that can control the IoT and control multicast communications. The first authentication is at network linking where we used a 256-bit keyless encryption technique. Machine learning-based chaotic map key generation authenticates the GKE. Finally, MD5 establishes the system key. 3S-IoT is smart to detect any tempering with the devices. It stores signatures of the connected devices. The algorithm reports any attempt to change or temper a device. 3S-IoT can thwart attacks such as Distributed Denial of Service (DDoS), Man-in-the-Middle (MiTM), phishing, and more. We calculated energy consumed, bandwidth, and the time taken to check the robustness of the proposed model. The results establish that 3S-IoT can efficiently deal with the attacks. The paper compares 3S-IoT with Benchmark algorithms.