## 1 Introduction  
The proliferation of internet of things (IoT) devices highlights the crucial importance of protecting sensitive information. These devices primarily collect measurements, effectively functioning as modern distributed measurement systems (DMSs), employed in diverse sectors such as wellness, home and industrial automation, education, power generation, smart agriculture, and safety applications. According to Check Point Research, IoT devices have faced a surge in cyber attacks this year. Early in 2023, the number of weekly attacks per organization rose by 41% over the same period the year before, with the education and research sectors experiencing the greatest increase in attack frequency. On average, organizations experienced nearly 60 attacks per week targeting IoT devices, marking a significant rise from 2022 and more than triple the attacks recorded two years ago. In the realm of IoT communication, developers have access to a variety of protocols for designing and deploying bidirectional communication channels, including message queuing telemetry transport (MQTT), hypertext transfer protocol (HTTP), constrained application protocol (CoAP), and WebSockets. The choice of protocol depends on hardware constraints and specific application requirements. This study focuses on MQTT due to its lightweight nature and publish-subscribe model, which aligns well with many IoT communication patterns, particularly in resource-constrained environments. However, we acknowledge that MQTT, like any protocol, has its limitations and may not be the optimal choice for all IoT scenarios. The surge in cyberattacks can be largely attributed to the widespread adoption of internet-connected IoT devices, especially those used in home automation systems and smart building technologies. Additional significant factors include users' limited understanding of cybersecurity risks, the race for a first-mover advantage in the market, the swift expansion of connected devices, and constrained security investments due to slim profit margins. Various techniques are employed to maintain service quality and ensure safety, but these often come at the cost of reduced network efficiency. This reduction can lead to delays in measurement data transmission, potentially compromising evaluation accuracy and introducing vulnerabilities or system failures. This study explores a security-centric virtual local area network (VLAN) strategy and the limitations of IoT hardware, given the varied landscape of IoT devices and their connectivity. The research implements local MQTT brokers and employs transport layer security (TLS) tunnels for sensor data at the local level. A secure sockets layer (SSL) tunnel is utilized to transmit TLS-encrypted information to a centralized cloud broker. The findings are extrapolated from an analysis of a worst-case scenario, providing broadly applicable insights. This focused attention stems from multiple factors. The rapid proliferation of internet-connected IoT devices enables remote control capabilities. The tight economic margins in the home automation sector restrict investments in security measures. The importance of swift market entry drives companies to compete for early adopter advantages. Additionally, limited cybersecurity knowledge among end-users often leads to cost considerations taking precedence over security precautions. When considering MQTT for IoT deployments, scalability becomes a crucial factor. Two key considerations are: (1) whether MQTT is the right protocol for the scale of the deployment, and (2) what infrastructure and network capabilities are necessary to handle increased traffic over MQTT. While MQTT is widely used and suitable for many IoT applications, alternatives like lightweight machine-to-machine (LWM2M) may be more appropriate for certain large-scale, long-term enterprise deployments. To address these security concerns while maintaining compatibility with MQTT brokers, we have tested and identified secure open secure sockets layer (OpenSSL) cipher suites.