## 4 Security Threats and Attack Methods in Blockchain-Based Supply Chain Management
### IoT Integration and Security Vulnerabilities  
The increased use of IoT devices in blockchain-based supply chains has significantly enhanced the transparency, efficiency, and traceability of various operational processes, ranging from logistics to inventory management. However, the proliferation of IoT devices has simultaneously created an environment susceptible to widespread threats due to inadequate security measures within these devices. While blockchain technology provides critical advantages, such as data integrity and immutability, through its distributed ledger structure, ensuring the protection of IoT components at the edges of the supply chain and maintaining secure, continuous data flows represent a complex, multi-dimensional challenge.  
* _DoS/DDoS attacks_: Denial of Service (DoS), one of the most prevalent and impactful attacks targeting IoT devices, aims to prevent legitimate users from accessing data and services promptly, typically by isolating devices from the network or exhausting available resources. Distributed Denial of Service (DDoS) attacks differ from DoS attacks in terms of the resources utilized to launch the attack. In DDoS attacks, multiple devices, such as desktop computers, servers, IoT devices, or other network-connected equipment, are simultaneously utilized to perform the attack [72; 73; 74; 75; 76], as depicted in Figure 5.  
* _MitM attacks in IoT network_: MitM attacks occur during data transmission between IoT devices and the blockchain network, potentially leading to the theft or alteration of critical supply chain data. In these attacks, the attacker positions themselves between two IoT nodes, intercepts communication, and manipulates data flows by interacting with both parties [77]. IoT components commonly utilized in supply chains, such as RFID devices and smart sensors, are particularly susceptible to these attacks. Attackers can register falsified data onto the blockchain, manipulating the product origin, temperature monitoring, or delivery information. This may result in counterfeit products appearing authentic and severely compromising supply chain security. For instance, in a pharmaceutical supply chain, RFID tags and sensors record temperature data onto the blockchain. An attacker could intervene at the IoT node to inject false temperature data, causing improperly stored drugs to appear safe, potentially posing severe health risks. Implementing secure communication protocols and data encryption methods is essential to mitigate such attacks.
* _Spoofing attacks_: Spoofing attacks occur when malicious actors impersonate legitimate devices, users, or systems to gain unauthorized access [77]. These attacks utilize various methods, including IP spoofing, email spoofing, and targeting device authentication processes [78]. Attackers may deceive systems by transmitting falsified data packets or impersonating device identities to execute unauthorized operations. Spoofing attacks are especially common in IoT-based systems due to weaknesses in authentication mechanisms [77; 78]. In blockchain-based supply chains, these attacks can manifest through the introduction of fake IoT devices or nodes that generate incorrect data. For example, counterfeit RFID readers or sensors integrated into a supply chain network could provide false information about the product location, temperature, or delivery status. Additionally, fake nodes might record inaccurate inventory data on the blockchain, manipulating stock levels or falsely indicating that non-existent products have been delivered. Such attacks compromise system integrity, causing reliability and transparency issues within supply chain processes.