## 1 Introduction
### Methodology  
This study applies a multi-layered and structured review methodology to evaluate how blockchain technologies enhance SCM, with particular attention to security, traceability, and data integrity. The methodological approach comprises the following stages:  
1. _The selection of studies and data sources_: A wide range of peer-reviewed journal articles, industrial white papers, and case studies were collected from recognized scientific databases, such as IEEE Xplore, Elsevier, Springer, MDPI, Wiley, ACM, and Taylor & Francis, and Emerald. No single publisher was prioritized. Instead, studies were selected based on their relevance to blockchain applications in SCM, particularly those addressing security vulnerabilities, traceability mechanisms, and data integrity concern. 2. _Timeframe and inclusion criteria_: In selecting the references for this study, priority was given to recent and high-impact publications that reflect the evolving landscape of blockchain-enabled supply chain systems. While emerging research was emphasizedto ensure relevance, foundational works were also incorporated to provide theoretical completeness and contextual continuity. * _Search strategy and keywords_: Keyword-based searches were conducted using combinations of terms such as \"blockchain supply chain security\", \"blockchain traceability\", \"data integrity in blockchain SCM\", \"smart contract vulnerabilities\", \"cross-chain interoperability\", \"privacy-preserving blockchain mechanisms\", \"confidential transactions in SCM\", and \"blockchain for humanitarian logistics\". These search queries were carefully selected to capture recent advancements and reflect the evolving technological and systemic challenges discussed in the literature. * _The thematic classification of supply chain risks and blockchain-based mitigations_: The identified studies were classified based on recurring SCM risk categories, including product counterfeiting and authenticity concerns, data tampering and inconsistency, limited traceability across multi-tier networks, and Internet of Things (IoT)-related security weaknesses. Each risk category was analyzed alongside relevant blockchain-based mechanisms, such as smart contracts for automation and enforcement, cryptographic hashing for data integrity, decentralized consensus protocols for trust-building, and oracles and interoperability standards for external data integration. * _The sectoral assessment of blockchain applications in SCM_: Blockchain adoption was analyzed across logistics, agriculture, food, healthcare, and retail supply chains. This stage aimed to extract
* Adoption variations across sectors;
* Context-specific implementation challenges;
* Legal and regulatory concerns;
* Sector-specific use cases demonstrating blockchain's impact on traceability, security, and data reliability. * _The comparative evaluation of blockchain's contribution to SCM pillars_: this study further assessed how blockchain addresses the core pillars of SCM:
* _Security:_ by enabling tamper resistance, fraud prevention, and secure access control;
* _Traceability:_ through real-time visibility, end-to-end product tracking, and provenance assurance;
* _Data integrity:_ via synchronized, immutable ledgers shared across stakeholders. * _The visualization and synthesis of the findings_: To enhance clarity and comparative insight, the results are presented using structured tables, conceptual mappings, and thematic summaries. These visual elements highlight the trade-offs among blockchain technologies across different supply chain layers, offering practical guidance for future research and system design under evolving systemic demands. The remainder of this paper is structured as follows. In Section 2, the major security threats encountered in traditional supply chains are analyzed and categorized under the headings of the lack of traceability, data integrity issues, counterfeit products, IoT vulnerabilities, and cyberattacks.