# TrustShare: Secure and Trusted Blockchain Framework for Threat Intelligence Sharing
## 2 Background
### Private Blockchain
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Feature** & **Hyperledger Fabric** & **Ethereum** & **Quorum** & **R3 Corda** \\ \hline \multirow{2}{*}{Consensus Mechanism} & Practical Byzantine Fault Tolerance (PBFT) & \multirow{2}{*}{Proof of Stake (PoS)} & \multirow{2}{*}{Istanbul BFT (IBFT)} & \multirow{2}{*}{RAFT consensus} \\ \hline Smart Contracts & Chaincode (Go and Java) & & & Smart Contracts (Solidity and Vyper) & Contracts (Kotlin and Java) \\ \hline \multirow{2}{*}{Privacy} & Channel-based privacy & Limited privacy features & Private transactions with Constellation & Corda Firewall and transaction privacy \\ \hline \multirow{2}{*}{Token/Currency} & Customizable (No built-in currency) & Ether (ETH) & Quorum Token (Quorum) & Customisable (No built-in currency) \\ \hline \multirow{2}{*}{Permissioning} & Granular control with Membership Services & Public and private networks & Permissions for nodes and transactions & Access Control in Corda Network \\ \hline \multirow{2}{*}{Performance and Scalability} & High scalability with modular architecture & Scalability challenges, higher latency & Scalability improvements, moderate latency & Designed for scalability and performance \\ \hline \multirow{2}{*}{Development Community} & Active development & Large and an active community & Developed by JPMorgan, active community & Active community with enterprise focus \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Comparison of private ledgers. each solution offers possibilities with varying levels of robustness. Hyperledger Fabric uses the Practical Byzantine Fault Tolerance (PBFT) consensus technique and also supports BFT-based solutions. Quorum's consensus protocols include Istanbul BFT (IBFT). R3 Corda also supports consensus methods based on RAFT consensus. Private Ethereum blockchains, on the other hand, can use the proof of stake (PoS) protocol. Notably, unlike Ethereum, other blockchain options do not require native coins for intelligent functioning. Ethereum, on the other hand, requires Ether to charge computational fees. We did not select Quorum or Corda because they are mostly used for financial applications. Hyperledger Fabric has less community and research support than Ethereum. Ethereum, on the other hand, has less throughput and more delay than Hyperledger Fabric [25; 26]. There are additional crucial considerations when selecting Hyperledger Fabric as any currency is unacceptable. On top of that, general-purpose languages are supported. Last but not least, many studies are working to improve Hyperledger Fabric's security, performance, and reliability issues with scalability [27; 28; 29]. Several features of the private blockchain solutions covered in [25] are compared, and the results of the research analysis can be seen in Table 3.  
Hyperledger Fabric stands as the cornerstone of a private permissioned blockchain framework meticulously chosen to craft a proof of concept (PoC) for threat information sharing. Through this option, we aim to optimize the seamless exchange of threat information among trusted organizations. In enhancing threat intelligence sharing, organizations must prioritize secure communication of threat data through encrypted or private channels. This approach ensures confidentiality and leverages trusted infrastructure to automate threat sharing, ultimately reducing threat detection and incident response times. Hyperledger Fabric plays a vital role in this context by emphasizing rigorous identity verification for all participating entities [20]. Utilizing chaincode, similar to Ethereum's smart contracts and writable in Java, JavaScript, or Go, a consortium of companies can seamlessly coordinate their own blockchains within the framework [20]. Hyperledger Fabric's intentional design emphasizes modularity, scalability, and versatility, forming a robust foundation for privacy, confidentiality, and scalability.