SUGISAKAMASANORI

Journal of Advances in Artificial Life Robotics
Vol. 3(4); March (2023), pp. 205–208
ON LINE ISSN 2435-8061; ISSN-L 2435-8061
https://alife-robotics.org/jallr.html

Research Article

Utilizing Blockchain to Monitor the Functioning of Devices inIndustrial Control Systems
I-Hsien Liu1, Chien-Hsin Wu1, Jung-Shian Li1, Chu-Fen Li2
Department of Electrical Engineering / Institute of Computer and Communication Engineering, National Cheng Kung University, No.1, University Rd.,
East Dist., Tainan City 701401, Taiwan
2Department of Finance, National Formosa University, No.64, Wunhua Rd., Huwei Township, Yunlin County 632301, Taiwan
1

ARTICLE I N FO
Article History
Received 08 October 2022
Accepted 04 May 2023
Keywords
Cyber security
Blockchain
PLC
ICS security

ABSTRACT

Programmable logic controllers, or PLCs for short, is ubiquitous in the field of industrial
automation. These devices are used to control and monitor a variety of processes related toproduction, ensuring that everything runs smoothly and efficiently. Unfortunately, there arecurrently no reliable means of verifying the accuracy and reliability of these devices, which canlead to serious consequences in the event of an error or malfunction. To address this issue,
researchers are exploring the use of advanced technologies such as blockchain to provide greatertransparency and security PLC operations.
© 2022 The Author. Published by Sugisaka Masanori at ALife Robotics Corporation Ltd.
This is an open access article distributed under the CC BY-NC 4.0 license(http://creativecommons.org/licenses/by-nc/4.0/).

In light of the Programmable Logic Controller's (PLC)
foundational
advantages,
encompassing
itsstraightforwardness, sturdiness, and dependability, thecriticality of ensuring its reliability is amplified when theequipment involved holds the potential to causesignificant financial losses, ranging from thousands toeven millions of dollars. Maintaining a high degree ofconfidence in the dependability of the Programmable
Logic Controller (PLC) is paramount for control
engineers and technical staff, as it allows for seamlessand expedient troubleshooting in the face of errors. The
original design of the PLC revolved around its function
as an automated control and development tool, with ahighly circumscribed scope of application, primarily
confined to industry network equipment. Consequently,
the device's limited adaptability proved a significant
obstacle to its wider utilization by external third-party
entities, beyond the industry network's purview..;
however, with the rapid development of the Internet andthe Internet of Things, and the contingency of intelligent

1. Introduction
In control systems, a programmable logic controller(PLC) serves as a crucial device comprised of variouscomponents, such as an input-output module (I/Omodule), actuators, and sensors. Within the system, thesensors are responsible for detecting either a switching
signal, which may involve a photoelectric switch or amaterial position switch, or an analog signal such astemperature or pressure from a given site. Subsequently,
the I/O module proceeds to transfer the signal from thesensor to the PLC, enabling the central processing unit
(CPU) to initiate the signal process. The output module
then converts the processed signal into a control signal
and dispatches it to the actuator. The actuator
subsequently carries out a specific operation on thecontrolled object, marking a vital step in the overall
control process.

Corresponding author’s E-mail: jsli@mail.ncku.edu.tw, chwu@cans.ee.ncku.edu.tw, ihliu@cans.ee.ncku.edu.tw, chufenli@gmail.com URL:
www.ncku.edu.tw, www.nfu.edu.tw

205automation is optimized using the PLC B network layer,
improving data refresh performance. However, malicious
attacks on the PLC during communication have beenobserved, making ongoing defense and adaptation crucial[2].
2.2. PLC’s operating mode
The perpetrator alters the operational status of the
Operational Technology (OT) device. Behold, theinsidiousness of the malefactor as they lay siege to theheart of Programmable Logic Controller (PLC)
technology. Cunningly, they deploy a plethora ofnefarious methods to manipulate the operational status ofthese machines, leaving chaos and destruction in theirwake. Alas, in their devilish quest, they may exploit theportals of data exchange known as APIs - gateways thatfacilitate communication between machines anddevelopers. Will we rise to the challenge and thwart theattacker, or fall prey to their treachery? Attackers also
have the opportunity to execute specific functions ormalicious attack instructions through APIs [3].

Fig. 1. System architecture.

hardware, industrial PLC has become more accessible tothe public in recent years. In order to effectively identify
and address issues, proper documentation of instructions
can play a crucial role in enhancing performance. To
achieve this, blockchain technology can be utilized todevelop a decentralized anti-tampering system for
Programmable Logic Controller (PLC) instructions. By
recording these instructions on the block chain, any
potential tampering or security breaches can be detected,
with the original instructions retrievable from theunalterable blockchain ledger. This approach would
provide a secure and trustworthy means of preserving theintegrity and security of PLC instructions, mitigating therisk of tampering and related failures.

2.3. Malicious PLC attack
Exploiting Programmable Logic Controllers (PLCs) caninvolve using data that's not typically included in static
or offline project files. This method can turn the PLCs
into weapons, allowing for the execution of code during
project connection or upload. Through this medium ofattack, the target is not a PLC, such as the notorious
Stuxnet[4] malware that secretly changes PLC logic tocause physical damage. Their objective is not to directly
attack the PLC itself, but to leverage it as a pivot point
for targeting the engineers responsible for its
programming and maintenance, in order to gain more
extensive entry into the OT (Operational Technology)
network. Researchers have discovered that all
vulnerabilities in automation security were found in theengineering workstation software, not in the PLC
hardware. This underscores the importance of securing
not just the hardware, but also the software componentsof the system. Typically, the reason why vulnerabilities
exist is due to the complete trust the software places inthe data originating from the Programmable LogicController (PLC), rendering the software vulnerable toattack and eliminating the need for exhaustive securitychecks.

2. BackgroundIn this chapter, we Chiefly discuss the current attacks andrisks of the ICS (Industrial Control System). At the 2016
Black Hat European Security Conference, Ali Abbasi, agraduate student, and Majid Hashemi, a Quarkslab R&D
engineer, proposed that a hostile attacker can destroy andmanipulate natural operations managed by aprogrammable logic controller (PLC) without being
detected [1].
2.1. Ethernet
Witness as Ethernet and TCP/IP protocols unite in adance of communication, forming the very foundation
upon which this technological marvel stands! In every
conceivable circumstance, TCP/IP communication is
fully supported, beckoning forth a world of seamless
interconnectivity. Real-time communication for206

Fig. 2.Transaction Process

Fig. 2. System architecture.

2.4. Peer-to-peer

3.2. Blockchain-based transaction process

In traditional web architecture, all resources are placedon the same server, and users who need to search theserver. Peer to Peer (P2P) networks are all responsible forstoring all or parts of all data. In addition to making
requests to other IP addresses, they also need to be
responsible for processing received requests, acting as
both Client and Server [5].

When chaining blocks together, four fundamental
components are utilized, namely: the hash value of theprevious block, transaction information, a nonce variable,
and the hash of the current block. The set up is shown in
Fig.2.
Step 1: PLC outlet instructions, including gateswitch
and so forth.
Step 2: When an instruction is sent, they are sent to theblockchain as well to exchange information.
Step 3: Override the hash code feature in the block,wrap the information and time it was obtained
as a nonce variable.
Step 4: Set the difficulty to get the hash value.
Step 5: Hash through the blockchain

3. System ArchitectureThis section provides an overview of the proposed
approach and framework. Some adjustments have been
made to the traditional network configuration andconfirmation system to make the blockchain running in
PLC more compatible.
3.1. Network model

4. Conclusion

The architecture we designed shown in Fig.1. toimplement block chain on PLC execution. When the PLC
sends instructions, they are connected to the block chain
simultaneously.
In this model, the functioning of a chain of PLCs isoutlined. As each instruction is executed, it is sent to theblockchain program in real-time and transformed into
input data within the blockchain. The information
contained within the Modbus packet is placed in the"nonce" field and subsequently transmitted onto theblockchain. By leveraging the immutable nature ofblockchain technology, it becomes possible to effectively
manage information stored within Programmable Logic
Controllers (PLCs) and record the transaction process. If
the transaction log is secured in a block, the log contents
are not easily changed.

As time progresses and technology advances, themethods employed to attack Industrial Control Systems(ICS) are becoming increasingly diverse, thus making
ICS network security a pressing research topic.To
safeguard the integrity of ICS packet information duringtransmission, this paper proposes utilizing the immutable
nature of blockchain technology to record theinstructions for PLC packet transmission. This way, inthe event of a future attack, unaltered records can beaccessed to determine where the issue originated.
Acknowledgment
This work was supported by the Water Resources
Agency (WRA) under the Ministry of Economic Affairs(MOEA) and the National Science and Technology
207

Dr. Jung-Shian Li

Council (NSTC) in Taiwan under contract numbers 1112218-E-006-010-MBK.

He is a full Professor in the
DepartmentofElectricalEngineering, National Cheng Kung
University, Taiwan. He graduatedfrom the National Taiwan University,Taiwan, with B.S. in 1990 and M.S.
degrees in 1992 in ElectricalEngineering. He obtained his PhD in
1999 in Computer Science from theTechnical University of Berlin, Germany. He teaches
communication courses and his research interests include
wired and wireless network protocol design, network
security, and network management. He is currently
involved in funded research projects dealing with opticalnetwork, VANET, Cloud security and resource allocation,and IP QoS architectures. He is the director of Taiwan
Information Security Center @ National Cheng Kung
University..

References
1. Abbasi A., & Hashemi M., “Ghost in the PLC: Designingan Undetectable Programmable Logic Controller Rootkit
via Pin Control Attack”, Black Hat Europe 2016(pp. 1-35).
2. Wikipedia contributors. (2022, November 4). Ethernet. In
Wikipedia, The Free Encyclopedia.
https://en.wikipedia.org/w/index.php?title=Ethernet&oldi
d=1120015826
3. ATT&CK for ICS - Execution(2).(2021)
https://ithelp.ithome.com.tw/m/articles/10275404
4. Wikipedia contributors. (2022, November 14). Stuxnet. In
Wikipedia, The Free Encyclopedia.
https://en.wikipedia.org/w/index.php?title=Stuxnet&oldi
d=1121937222
5. R. Gaeta and M. Sereno, "Generalized Probabilistic
Flooding in Unstructured Peer-to-Peer Networks," inIEEE Transactions on Parallel and Distributed Systems,vol. 22, no. 12, pp. 2055-2062, Dec. 2011

Prof. Chu-Fen Li

She is an Associate Professor in theDepartment of Finance at theNational
FormosaUniversity,Taiwan. She received her PhD in
information management, financeand banking from the EuropaUniversität Viadrina Frankfurt,
Germany. Her current researchinterests include intelligence finance,
e-commerce security, financialtechnology, IoT security management, as well as financial
institutions and markets. Her papers have been publishedin several international refereed journals such as European
Journal of Operational Research, Journal of System andSoftware, International Journal of Information andManagement Sciences, Asia Journal of Management andHumanity Sciences, and others.

Authors Introduction
Dr. I-Hsien Liu

He is a research fellow in theTaiwan
Information
Security
Center @ National Cheng Kung
University (TWISC@NCKU) andDepartmentofElectricalEngineering, National Cheng Kung
University, Taiwan. He obtained
his PhD in 2015 in Computer andCommunication Engineering fromthe National Cheng Kung University. His interests are
Wireless
Network,Group
Cyber-Security,Communication and Reliable Transmission. He is thedeputy director of Taiwan Information Security Center @National Cheng Kung University.
Ms. Chien-Hsin Wu

She was born in Tainan, Taiwan in1999. She is acquiring the master’s
degree in Department of ElectricalEngineering/Institute of Computerand Communication Engineering,
National Cheng Kung University inTaiwan. She received her B.S.
degree from the Department ofCommunication
Engineering,
National Taipei University, Taiwan in 2021. Her interests
are Cyber Security.

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