The internet of things (IoT) is defined as a collection of autonomous devices that connect and network with each other via the Internet without the requirement for human interaction. It enhances daily our lives such as through personal devices, healthcare sensing, retail sensing, and industrial control, as well as the smart homes, smart cities, and smart supply chains. Although the IoT offers significant benefits, it has inherent issues, including security and privacy risks, memory size limitations, and processing capability challenges. This paper describes the application of elliptic curve cryptography (ECC) in a simulated IoT environment to ensure the confidentiality of data passed between the connected devices. Scalar multiplication represents the main operation of ECC, and it is primarily used for key generation, encryption, and decryption. The aim of this paper is to evaluate and show the efficiency of adapt lightweight ECC with an IoT devices. In the study outlined in this paper, scalar multiplication was implemented on Raspberry Pi4 and processing time and consumed energy were measured to compare the performance. The comparison was made on the scalar multiplication of both fast and basic ECC algorithms. The result of the performance test revealed that a fast scalar multiplication reduced the computation time in comparison with basic scalar multiplication while consuming a similar level of energy.