## 5 Blockchain-Based Supply Chain Security Solutions and Integration Models
### Data Privacy with Zero-Knowledge Proof (ZKP) and Confidential Transactions
#### 5.3.2 Architectural Model for Cross-Chain Supply Chains and Smart Contract Design
For example, exposing supplier identities, pricing structures, or strategic logistics data can lead to competitive disadvantages [85]. Although emerging solutions, such as ZKPs and confidential transactions, aim to mitigate this conflict, their maturity for supply chain implementations remains limited [87, 88]. ### Smart Contracts and Their Operational Limitations

Numerous external factors, such as delivery delays, weather disruptions, or logistical bottlenecks, can affect contractual conditions in supply chains. However, the rigid and deterministic nature of smart contracts may struggle to reflect such real-world variability [31, 34]. For instance, an automatic penalty triggered by a delayed delivery could undermine operational flexibility or human judgment. Additionally, vulnerabilities in smart contract code pose considerable security risks for large-scale supply chain operations [36]. These concerns are further presented in Table 16, which outlines the key technical limitations of smart contracts and their practical implications within supply chain environments. ### Cross-Chain Interoperability and Standardization Issues

Global supply chains span across countries and industries, involving numerous heterogeneous systems. Yet, most blockchain solutions function as isolated ecosystems, limiting \begin{table}
\begin{tabular}{l l l} \hline \hline
**Smart Contract Limitation** & **Implications for Supply Chains** & **References** \\ \hline Immutable code & Inflexible agreements & [34, 36] \\ Lack of legal enforceability & Legal uncertainty in dispute resolution & [31, 36] \\ Oracle dependency & Critical reliance on external data sources & [31, 34] \\ Code vulnerabilities & Risk of operational disruption and & \\  & reputational damage & [27, 36] \\ \hline \hline \end{tabular}
\end{table} 
Table 16: Limitations of smart contracts and their implications for supply chains. end-to-end visibility and seamless data exchange [97; 98]. Cross-chain communication is hindered not only by technical incompatibility but also by the absence of common standards and diverse data policies. Although emerging solutions aim to bridge this gap, their integration into supply-chain-specific scenarios remains underdeveloped and insufficiently tested [100]. ### Sustainability Concerns and Green Blockchain

In recent years, supply chains have increasingly emphasized sustainability metrics, including the carbon footprint, ESG (Environmental, Social, and Governance) compliance, and green logistics. In this regard, blockchain's transparency and traceability can support environmental goals. However, the energy consumption of certain consensus mechanisms, particularly proof-of-work, raises concerns about alignment with sustainability objectives. Although alternatives such as proof-of-stake offer greater efficiency, energy sustainability in large-scale logistics systems remains an open debate [108; 137]. ### The Human Factor: Organizational Resistance and Skill Gaps

One of the most significant barriers to digital transformation in supply chains is not technological but organizational. Reconfiguring internal processes around blockchain logic often generates resistance and uncertainty among employees [43]. Furthermore, the shortage of skilled personnel in blockchain technologies hampers implementation. Therefore, beyond technical readiness, synchronized organizational transformation strategies are essential for successful adoption [136]. ### The Role of Emerging Technologies in Blockchain-Enabled Supply Chains

Beyond architectural and interoperability concerns, the role of emerging technologies further reshapes blockchain-enabled SCM frameworks. The increasing complexity and interconnectedness of modern supply chains, driven by real-time responsiveness, multi-actor coordination, and global scalability, has introduced new systemic demands on data security, traceability, and integrity.