The position paper, titled “Enhancing SDN Security for IoT-related deployments through Blockchain” by C. Tselios, I. Politis and S. Kotsopoulos, explains how the blockchain paradigm can potentially be applied to prevent vulnerabilities of SDN (Software Defined Networking) and IoT (Internet of things) systems. For those unfamiliar with SDN, the authors describe it as shifting a network from relying on physical switches and routers to a more centralized approach, where an administrator could control aspects of the network from one hub. Often, SDN is used to administer large cloud networks. The authors say that SDN and IoT are both prime targets for malicious hackers and believe that blockchain could be implemented to secure the many vulnerabilities that currently exist.

I strongly agreed with their stance that using blockchain can better secure our systems. They describe how the distributed ledger used in a blockchain method ensures that all parties in the system have access to the same incoming “transactions” (or data changes) since the system is transparent. This ensures that all parties can actively validate the accuracy of data due to its existence in multiple locations across the system. In centralized systems, this is different because one location contains all data, and if it were breached there would be no way for the parties using the system to know which data was tampered with. This key difference is why blockchain could specifically secure SDNs since, at its core, it provides a way for an entire network to be managed from a centralized location. If this information was spread out between many parties of the system, the computers could track and ensure that all changes in the system were valid.

This same distributed ledger used by blockchain could also greatly improve the security for the Internet of Things. IoT devices are inherently more vulnerable to cyber attacks because they are designed to work as a piece of a large system of other devices. This scale makes it hard to ensure that every single device is being updated on a constant basis and tracked to ensure there has not been a breach of security. This could be prevented by allowing blockchain to act as a “distributed archive” for the system. This would allow “authorized nodes to instantly track and verify data that is generated by IoT devices, once recorded in this data structure, regardless their volume or the overall number of sources” according to the authors. This interconnectivity could ensure that IoT devices would not be susceptible to the types of cyber attacks that have dominated the headlines in 2017.

According to this paper, blockchain’s distributed ledger is a strong contender to solve many vulnerabilities of our networks and devices. It could prevent networks from being breached and tampered with from a single point of entry.



Tselios, C., Politis, I., & Kotsopoulos, S. Enhancing SDN Security for IoT-related deployments through Blockchain.