## 5 Blockchain-Based Supply Chain Security Solutions and Integration Models
### Security Comparison of Permissioned and Permissionless Blockchains  
Blockchains are classified into two main categories based on access control: permissioned and permissionless. Permissioned blockchains, such as Hyperledger Fabric, permit only authorized users to perform transactions, whereas permissionless blockchains, such as Bitcoin and Ethereum, allow open participation to anyone [79]. Sidechains bridge these two types of blockchains, increasing the transaction capacity and facilitating asset transfers. Table 5 provides a detailed comparative analysis between permissionless and permissioned blockchain systems, specifically highlighting Ethereum and Hyperledger Fabric as widely adopted representatives of these blockchain types. Permissionless blockchains are decentralized systems that are open to participation from any user without requiring a central authority. These systems typically utilize cryptographic consensus mechanisms, such as proof-of-work (PoW) or proof-of-stake (PoS), to achieve a consensus among nodes. Bitcoin pioneered this blockchain category by offering an immutable ledger for transparent and verifiable transactions. Other permissionless blockchains, such as Ethereum, enable more complex applications through smart contracts. However, permissionless blockchains face several challenges, including intensive computational requirements for transaction validation, limited transaction capacity, and concerns regarding data privacy [80]. \begin{table}
\begin{tabular}{p{113.8 pt} p{113.8 pt} p{113.8 pt}} \hline \hline
**Features and Security Criteria** & **Permissionless Blockchain** & **\#ethereum Blockchain** & **Permissioned Blockchain** & **\#VIPERledger FABRIC** \\ \hline Governance & Community-driven, open governance (Ethereum Developers). & Consortium-based governance (Linux Foundation). & Consortium-based governance (Linux Foundation). \\ Permission Structure & Open participation, no access restrictions. DeFi, NFTs, gaming, decentralized apps (dApps), public sector. & Restricted participation, controlled access. Supply chain, finance, healthcare, logistics, enterprise applications. \\ Consensus & Proof-of-stake (PoS), formerly & Modular: Raft, Kafka, PBFT, customizable. \\ Mechanisms & Proof-of-work (PoW). & Chaincode (smart contracts) written in Go, JavaScript. JavaScript. \\ Smart Contracts & Solidity language, Ethereum Virtual Machine (EVM), widely decentralized. & Chaincode (smart contracts) written in Go, JavaScript. JavaScript. \\ Data Privacy and Anonymity & Low privacy, pseudonymous transparency, fully transparent ledger. & High privacy, confidential transactions, channel-based privacy control. \\ Trust and Inturability & Fully immutable, trustless validation by all & Controlled immutability, selective trust, transactions reversible by governance. \\ Attack Resistance & Risk of 51\% attacks, computationally intensive & Reduced risk due to restricted participation (access control, stronger identity authentication). \\ Data Integrity and Security & High (cryptographic validation, decentralized verification). & High (access control, stronger identity authentication). \\ Scalability & Lower transaction throughput (\(\sim\)15–30 TPS), limited scalability. & Higher transaction throughput (hundreds to thousands TPS), highly scalable. \\ Authorization and Access & No explicit authorization, open for all users. & Explicit authorization mechanisms, controlled user roles and permissions. \\ Operational Efficiency Consumption & Moderate (due to consensus mechanisms and decentralization). & High (fast transaction validation, lower latency). \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Comparative analysis of permissionless and permissioned blockchains. Permissioned blockchains are closed systems that permit participation exclusively to authorized users, specifically designed for enterprise-level use. In these blockchains, network management is handled by selected organizations, and transactions can only be executed by verified participants.