Rising as a technology, the Internet of Things (IoT) is predicted to link billions of items to the Internet in not-too-distant future. More and more products including wearables, smart home systems, and industrial automation tools are being Internet-connected with time. IoT devices mainly transmit data using wireless communication networks, which leads to more vulnerabilities such as man-in-the-middle attacks and eavesdropping. This study aims to explore and analyze the currently available security strategies to protect IoT devices, especially those with limited resources such as computing power and energy. The fast spread of IoT devices presents serious security issues for maintaining data confidentiality and integrity as well as for guarding data transfer. This work aims to reach these objectives by addressing the two following research questions: What are the currently available security strategies for IoT devices? what are the main security concerns IoT devices face? The study reviews and evaluates several lightweight encryption algorithms, including TEA, XTEA, and dynamic AES, which provide a practical solution to improve data security without draining device resources. The study also discusses multi-layered security techniques, such as integrating the enhanced RSA algorithm with OTP and the SIT mechanism to provide a comprehensive framework for communication protection. Through this analysis, the study seeks to identify gaps in current research and provide recommendations for improving performance and effectiveness in IoT applications, which contributes to enhancing the reliability and security of these devices in their complex and changing environments.