## 4 Security Threats and Attack Methods in Blockchain-Based Supply Chain Management
### Traceability and Anti-Counterfeiting Measures  
Centralized structures and opaque data sharing in traditional supply chain systems create information gaps, significantly complicating anti-counterfeiting efforts [52]. In this regard, blockchain technology provides crucial contributions by transparently recording the movement of products along the supply chain onto an immutable ledger, thereby preventing the spread of counterfeit goods [7]. Nevertheless, despite blockchain's inherent advantages of security, auditability, and immutability, ensuring the accuracy and integrity of the data entered into the system remains a critical issue [53]. In particular, incorrect or incomplete data entry, when combined with the reliability concerns associated with off-chain data sources, poses a considerable threat to overall supply chain security. These security threats and attack methods are detailed below:  
* _Incorrect or incomplete data entry._ The accuracy of blockchain data depends directly on the reliability of the information provided at entry points. Incorrect or incomplete data entries can lead to flawed records on the blockchain, undermining anti-counterfeiting efforts [54]. For instance, if suppliers or manufacturers deliberately or negligently misreport product origins, consumer deception and market trust erosion become significant risks. * _Oracle vulnerabilities_: The reliability of external data sources constitutes a critical vulnerability in blockchain-based supply chains. The transfer of logistical data, quality control reports, and certificates onto the blockchain relies heavily on oracle mechanisms. However, oracles are susceptible to technical attacks and can be manipulated by malicious actors. Additionally, companies may provide false data to achieve competitive advantages, undermining the transparency and reliability of the entire system [55]. Due  
Figure 4: Classification of security threats and attack methods in blockchain-based supply chain. to blockchain's immutable nature, transactions based on incorrect data provided through oracles cannot be reversed, posing substantial risks for stakeholders [56]. Although solutions such as multi-source verification and reputation-based validation have been proposed, the absolute security of external data sources remains elusive. It is emphasized that oracle security should be supported not only by technical measures but also by regulatory frameworks [57]. A trust model using blockchain-based supply chain traceability has been proposed to overcome these oracle-related security concerns [58]. For instance, an Italian dairy company employed blockchain technology to combat product counterfeiting but had to implement additional measures to address oracle-related security risks. Independent certification authorities and incentive mechanisms were introduced to enhance the data accuracy and strengthen the system's reliability. * _Data deletion or modification_: The ability to alter historical records in traditional databases significantly increases the risk of manipulation and counterfeiting in supply chains. For example, manufacturers or distributors can retrospectively modify delivery records of products that fail quality standards, misrepresenting these products as safe or compliant. Although blockchain data are immutable, inadequate integration between blockchain and traditional systems or the failure to reflect certain records onto the blockchain continues to pose counterfeiting risks [47; 54]. Table 4 presents a comparative overview of various studies employing blockchain technology to combat counterfeiting. An Ethereum-based blockchain system was developed to prevent counterfeit products, allowing manufacturers to transparently record product information on the blockchain. This system enables consumers to independently verify product authenticity through smart contracts and digital signatures, providing a cost-effective, decentralized anti-counterfeiting solution [59].