The Fourth Industrial Revolution (Industry 4.0) has been the driving force towards the convergence of computer networks. The main notion behind Industry 4.0 is to leverage on big data analytics and machine learning to create business value and spur productivity growth. Concurrently, the growth of the “Internet-of-things” (IoT) has seen the emergence of more communication devices and platforms ride on the expanding internet bandwidth and connectivity. These have led to Smart City initiatives in numerous metropolitan cities and urbanised areas, where the seamless flow of information is being harnessed to manage assets and utilise resources more effectively and efficiently. However, due to the ease of interaction and increased connectivity among platforms, people and devices have laid the perfect conditions for cyber attacks to take place. Over the last decade, cyber attacks have grown in both frequency and scale. In 2017 alone, there were 5,207 breaches reported, exposing approximately 7.89 billion records and these have led to heavy financial losses and damages to corporate reputation.
A data diode is a hardware-enforced unidirectional data control network appliance which enables the transfer of data across physically separated networks to be done securely without the risks of any data leakage. Data is transmitted using one-way fibre optic communication thus it is physically impossible for data to flow in the opposite direction, even if the data diode malfunctions. The control of data flow is also enforced at the application layer by deliberate selection of appropriate communication protocols. In addition, the data diode can be deployed together with a file cleansing solution to ensure that malware does not infiltrate the closed network.