## 7 Conclusions  
In this work, we analyze the data monetization use case by creating a virtuous cycle of data flow incentivizing Vehicle_OEMs, RADAR_OEMs, and Vehicles who share the data. We exhibit the extensibility of the architecture to external systems and provide RADAR signature services offering global fairness, interoperability, privacy by design, asset data reputation, and a secure network. We further evaluate the cloud-based implementation and understand the Substrate hybrid consensus from an application-based blockchain with an embedded smart contract, including its BFT family consensus scalability limitations. However, we discuss some improvements that can further enhance the data monetization protocol as below:  
* Auction: Auctions can be made more transparent by a commit reveal scheme where there are no time-bound constraints and hidden bids are eventually public when all the bids are received and committed. * Privacy: Differential privacy [33] can be applied for more granular privacy control on the data ensuring more concealment than the masking techniques. Also, account abstraction based on the ERC 4337 [34] protocol can be considered for anonymizing network participants as an alternative to pseudonymization in our protocol. * Smart Contract: Smart contract embedded along with client runtime in our Substrate blockchain has better security than by deployment. But it has not been audited using tools like MythX [29], or legal aspects are offloaded, which can be considered in the future. * Interoperability: Substrate has both intra-chain and inter-chain communication extensibility. The inter-chain exchange in the form of Parachains has several limitations discussed in [35]. They are due to being monetary-based Proof of Stake Polkadot network for parachain slots, validator election transparency issues and governance problems due to the \"prime voter\" as well as 13 member council governance affecting decentralization. Also, there are liquidity issues with the Polkadot network due to economic reasons, and many parachains like Lido have ceased their operation. * Certification Proof: Hash-based chained certification can be replaced with Merkle proofs or Zero Knowledge proofs where any user can verify the proof without actual data revealed. * Consensus: Our implementation analyzes the hybrid consensus of AuRa, BABE, and GRANDPA available in Substrate necessary for our data monetization use case. Another consensus of Nominated Proof of Stake can be tested, available in Substrate Polkadot based on monetary conditions of currency called DOTS. It can be applied to our use case but needs monetary-based staking and slashing constraints [35]. In evaluating the hybrid consensus algorithms of Clique and BABE with GRANDPA in particular, we notice that there are issues of forks, and scalability impacting the throughput and finalization of the transaction in the blockchain. This behavior is exhibited even in our case of consortium participants with limited strength of nodes. This work, along with our evaluation works on Byzantine Fault-Tolerant (BFT) Algorithms of Practical Byzantine Fault Tolerance (PBFT), Clique, Istanbul Byzantine Fault Tolerance (IBFT), and Quorum Byzantine Fault Tolerance (QBFT) [16; 17; 18], confirms the drawbacks of these algorithms. They can be narrowed to scalability, security, forks, data consistency, and deadlock issues. To solve these problems, we propose an algorithm named CUBA in our other works [36; 37] which address these problems. It is a consortium-oriented BFT algorithm where the actions of the participant in terms of block proposal, voting, and round proposal are recorded in the form of utilitarian scores. These scores are then utilized to form the quorum for each round of the consensus process dynamically. Block validation is performed in two phases of intra-quorum and inter-quorum, which is evaluated on a cloud blockchain simulation network. It offers better performance, security, scalability, and finalization compared to Clique, PBFT, IBFT and QBFT consensus algorithms.