## 1 Introduction  
As the Internet of Things (IoT) and wireless communication continue to grow, they transform people's lives through progressive technologies, creating new opportunities for development and enhancing both quality of life and productivity. IoT has also made modern infrastructures more interconnected and optimized. Statista [1] noted there will be 4 billion connected IoT devices by the end of 2024. This growth shows that more and more people are using IoT to make their lives and work easier. Some devices use Wi-Fi to connect and send data, allowing users to control IoT devices by only one smartphone. However, as IoT devices become more common, cybersecurity becomes a serious issue. Many devices send sensitive data over public networks, making them easy to steal. Insecuredata transmission not only compromises personal privacy but also exposes vulnerabilities in essential systems that rely on IoT infrastructure. Strong cryptographic algorithms need to be used when transmitting data. Common encryption methods like the Advanced Encryption Standard (AES) and RSA are keeping data safe. They make it hard for attackers to break encrypted data easily. The cryptographic strength of AES and RSA imposes resource-intensive demands on attackers attempting to break the encryption. However, SCAs pose a significant threat by bypassing the mathematical security of these algorithms. SCAs exploit the physical characteristics emitted by encryption devices, such as power consumption [2], electromagnetic radiation [3], and thermal emissions [4], to infer encryption keys. These physical leakages often exhibit statistical correlations with the keys, allowing attackers to deduce them through sophisticated analysis. Current SCA defense strategies primarily focus on microcontrollers, utilizing techniques such as masking [5] and hiding [6] to minimize the observability of physical signals, thereby improving resistance to SCAs. Yet, as SCA techniques continue to evolve in complexity, traditional defenses have proven insufficient [7]. Furthermore, the rapid progress in quantum computing has introduced additional threats to existing security mechanisms. Consequently, the development of more robust defense strategies has become imperative. Recently, researchers have proposed an SCA method targeting Wi-Fi environments, which enables attackers to decrypt transmitted data without the need for access to the device's password [8]. This study highlights the significant threat that SCAs pose to modern information security. To address this challenge, the present research introduces a lightweight AES-128-based encryption key protection mechanism specifically designed for securing IoT communications. This mechanism effectively defends against SCAs without compromising system performance. In IoT devices, AES-128 has become the best encryption algorithm candidate due to its low computational overhead and power consumption [9]. Compared to other encryption methods, AES-128 not only provides sufficient encryption strength [10], but also operates with high efficiency. However, just relying on the encryption algorithm itself is not enough to ensure robust security. Especially in public network environments, IoT devices performing encryption operations may leak physical signals, which attackers can exploit to compromise encryption keys, thus threatening the overall security of the system. If smart home devices, such as access control or surveillance systems, fall victim to SCAs, personal privacy and sensitive data could be severely compromised [11]. Therefore, improving encryption key protection mechanisms for IoT devices is both a critical and urgent task. Furthermore, [PERSON] et al. [12] have proposed an enhanced Message Authentication Encryption (MAE) scheme based on the Physical Layer Key Generation (PKG), which improves encryption efficiency by 80.5% while consuming fewer computational resources. This advancement offers a more efficient security solution for resource-constrained IoT devices.