The increasing threat landscape in Industrial Control Systems (ICS) brings different risk profiles with comprehensive impacts on society and safety. The complexity of cybersecurity risk assessment increases with a variety of third-party software components that comprise a modern ICS supply chain. A central issue in software supply chain security is the evaluation whether the secure development lifecycle process (SDL) is being methodologically and continuously practiced by all vendors. In this paper, we investigate the possibility of using a decentralized, tamper-proof system that will provide trustworthy visibility of the SDL metrics over a certain period, to any authorized auditing party. Results of the research provide a model for creating a blockchain-based approach that allows inclusion of auditors through a consortium decision while responding to SDL use cases defined by this paper. The resulting blockchain architecture successfully responded to requirements mandated by the security management practice as defined by IEC 62443-4-1 standard.

Power grids are constantly evolving, and data changes are increasing. Operational technology (OT) is controlled by IT technologies in smart grids, where changes in the physical world impose changes in the software data model, as well as the continuous generation of data points, resulting in time series datasets. The increased need for processing large amounts of data combined with requirements to maintain and increase overall performances has created a significant challenge for traditional database solutions and relational database models. The main idea of this paper was to find and propose a graph model that will allow the retrieval of historical connectivity in a reduced time complexity. Furthermore, the research question was addressed by evaluating three different approaches where the results provide a foundation for the proposed design guidelines related to optimizing graph-based databases for a modern smart grid system. The results of the experiments demonstrated reduced time complexities from 3 to 5 times depending on the typical industry usage patterns and the selected graph model. This suggests that the design decision may severely affect the outcome for given smart grid use cases when using historical features in OT technologies. Therefore, the main contribution of the research is the proposed guidelines on how to design an optimal graph model that satisfies the described smart grid requirements.