# A Novel Software Architecture Solution with a Focus on Long-Term IoT Device Security Support
###### Abstract  
This paper presents a solution for upgrading a previous device model to an Industry 4.0 smart device, with the goal of maintaining high compatibility. A novel IoT architecture is presented that satisfies the characteristics of a smart device. We analysed existing IoT architectures and proposed a new architecture to achieve long-term security and usability. To ensure long-term security, we eliminated the possibility of device configuration outside the immediate vicinity of the device with a dedicated protocol. The security concepts of the existing architectures were also analysed and further modified. To improve compatibility with previous device models, we propose a new method to collect data from sensors by introducing a multithreaded microcontroller. We propose additional software components to ensure factory programming, maintenance, and cloud Big Data analysis. Based on our experiments, we adapted the algorithm to increase the accuracy of the temperature and flow sensors by using a temperature calibration device and known flow cycles. Measurement results are presented to confirm the successful upgrade. We designed a hardware architecture to ensure compatibility with previous and future device models. Issues with previous sensors encountered during the upgrade were discussed and resolved. A novel software architecture based on security for long-term IoT devices is proposed. s +
Footnote †: journal: Applied  
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cloud for storage and further analysis. The data are partially analysed in the edge device layer before being sent to the cloud [8]. To analyse large amounts of collected data from sensors or other smart communication devices in real time, Big Data technology combined with artificial intelligence and business intelligence is essential [9]. The efficient analysis of collected data inherently improves the quality of life, enables more informed decisions [10], reduces production costs and generates higher revenues. When automation is applied to industry, it is referred to as industrial IoT (IIoT)--a subset of IoT [11; 12]. In the IIoT concept, one of the main challenges is to ensure a high standard of reliability and security while working within the resource constraints of internet availability and computing power [7]. The telemetry of the product implemented with IIoT can be used to intelligently monitor the internal processes of the device throughout its life cycle. The life cycle consists of the manufacturing process, commissioning, service cycle and finally, the decommissioning of the product. The enhanced life cycle is part of the goals of Industry 4.0 [13] and allows the manufacturer to constantly monitor product performance in different environments. Life cycle monitoring, used for high-end products such as the ones in the automotive industry, can also be applied in other areas, in our case, manufacturing a beverage cooling device. The focus shifts from the production process to the life cycle of a product. Industry 4.0 refers to smart manufacturing, but also to the constant monitoring of the product during its life cycle in order to make decisions based on the information obtained. In Industry 3.0, the product was mostly improved through experience. Figure 1 illustrates the main changes from Industry 3.0 to Industry 4.0 [14]. In the modern world, one of the most important issues in implementing Industry 4.0 is security. In this paper, we propose a novel security-oriented software architecture concept suitable for a device with a lifetime of 15 years or more. Standard IoT architectures define three common layers: perception layer (device), network layer (connect), and application layer (manage) [15]. This architecture provides top-down and bottom-up communication of from layers with implemented security principles. Implemented security, especially cryptography, can become the issue considering long-term device usage. Unlikely device hardware updates combined with exploits in network security protocols pose a serious problem.