Potential Applications and Challenges for Blockchain in Industrial Automation

The previous article explained how blockchain works, why it’s secure, and introduced using blockchain for logistics, such as the supply chain and asset tracking. In this article, we will continue to provide examples and potential applications for blockchain in industrial automation.

Blockchain and IoT

The Internet of Things (IoT) has millions of applications worldwide but simultaneously has exposed many security risks. We often hear from the news that malicious actors hacked IoT products such as wireless cameras, Amazon Alexa, and smart thermostats and stole data.

Blockchain can help to close the gap on the security deficiency for IoT applications. Many IoT applications use MQTT for communication. MQTT can be secured by introducing blockchain-based OTP (one-time-password) authentication into its schema.

In figure 1, a user registers a remote device with the broker by sending an authentication request to the broker using a local device. The broker generates a transaction and initiates the function of a smart contract. It then generates an OTP and sends it back to the user. Afterward, the user publishes the OTP on the blockchain to demonstrate the originality of their authentication request.

Figure 1. IoT implemented with blockchain. Image used courtesy of U.S. National Library of Medicine

Since the OTP has an expiration, the user must call the smart contract from the local device to verify that the OTP has not expired. Once the OTP is validated, the remote device retrieves it from the blockchain and sends it to the broker. Finally, the broker retrieves the OTP from the blockchain and approves the device registration.

All of the above communications are performed through the Ethereum gateway, and the IoT application is working to generate and verify the OTP and communicate with the Ethereum gateway.

Industrial Control System (ICS) Cybersecurity with Blockchain

Another method to secure access control to the IoT devices and their data is using blockchain to store the device list and transactions. The blockchain can be designed on an Ethereum platform using Truffle Suite. Truffle Suite is a tool used to create smart contracts using Ethereum Virtual Machine (EVM). It creates a record-tracking and immutable database for authentication purposes and to keep transactions secure. The data in the immutable database cannot be deleted or updated.

The Ethereum blockchain created is a private network behind a firewall, and the server communicates to the Ethereum blockchain using HTTPGet and HTTPPost methods. The smart contract is designed to authenticate each transaction every time. Ethereum blockchain is used for the private blockchain network, and Java-based Solidity defines the contracts.

Blockchain and Process Control

A blockchain-based vertical integration architecture for a process automation system (PAS) can control and monitor an industrial process. A vertical integration collects data at the lowest field and device level and enables the information to travel to the highest level. And vice versa, from the highest level to the field devices such as changing setpoints for control loops.

Decentralized blockchain-based network architecture can be implemented in the vertical integration of PAS hierarchy levels, which works in parallel with the real-time system. This introduces the blockchain into the task orders such as compilation, execution, and monitoring, performed by the operator at the human-machine interface (HMI) level.

As shown in figure 2, the blockchain network is used as a middleware to connect the corporate management, plant management, and supervision levels, where each level is acting as a blockchain client and interacting with each other in a decentralized manner.

Process control level devices arbitrate communication between field devices and sensors through the programmable logic controller (PLC). It also communicates with the three levels of the PAS through smart contracts that define task execution and raw data collection, and perform access control and security management. The information can support business and manufacturing decision-making.

Figure 2. Process control implemented with blockchain. Image used courtesy of Cornell University [PDF]

In this architecture, the PLC device management and control information are stored in the ledgers in the blockchain network where transactions are validated. Each transaction is identified by a unique address and stores all relevant information to be exchanged among different levels in the PAS.

The Challenge Ahead with Blockchain

Even with the success of blockchain-based networks in cryptocurrency, blockchain cannot be copied and pasted into other industrial applications. Below are some of the challenges that need to be considered by blockchain developers for successfully integrating blockchain into industrial automation and manufacturing applications.

• Blockchain miner: In cryptocurrency, miners are rewarded monetarily when they solve a complex mathematical equation. In an industrial application, the miner’s tasks will have to be replaced by computational processes or units to perform these intensive responsibilities. This will increase the scope and resource required, and therefore, the cost to build the IoT or control network.
• Security: We still hear from the news occasionally that hackers find their way into emptying cryptocurrency users’ accounts. There are some security flaws in the blockchain network. The decentralized nature of blockchain can increase its security but also creates more targets for hackers to exploit. Researchers must find a better way to increase the security in the protocol layer.
• Speed: The time to mine 1 Bitcoin is 10 minutes because of the algorithm’s complexity and the time it needs to traverse in the mining network. It may be fine in a financial market, but it may not be feasible for a real-time control system. Researchers will have to increase bandwidth, encryption speed, and reduce waste of computing power for blockchain to be more applicable in industrial applications.
• Slow adoption: Blockchain is an ecosystem that requires broad adoption to work effectively. For example, tracking and tracing in supply chain networks would not only require an organization to adopt a blockchain network but also for its suppliers to adopt as well. Companies tend to be slow to adopt new technologies when they need to come up with a consensus with others. Different business entities must work together and trust each other to form compatible blockchains where security and transaction can work flawlessly among themselves.
• Skilled developers: Blockchain is an emerging technology. The skills required to develop and master it are not widely available in the marketplace. It is a challenge for an organization to acquire blockchain developers and engineers, and their salaries are highly competitive. This talent barrier acquisition may slow down integrating blockchain into legacy systems. However, as we have seen with other technologies, when there is a demand, educational institutions and the technical community can help catch up and supply enough trained workforces.

Even though there seems to be some challenges with blockchain, the good news is there is a lot of work in progress to combat these deficiencies. Organizations and technology leaders have recognized the benefits and potentials of blockchain, and they are investing in this technology. As with other new technologies, there will be time for blockchain to face a rigorous challenge before it becomes a mainstream adoption.

Only time can tell if cryptocurrency is a boom or bust. But the blockchain technology that it helps create will hold its value for a long time to come in the industrial application arena.