Proof-Of-Stake-Based Blockchain Frameworks for Smart Data Management

Over the last few years, the Proof-of-Stake (PoS) consensus mechanism has emerged as an efective solution to data management in various areas. However, developing the PoS mechanism requires thoughtful design and consideration to overcome signifcant challenges for diferent blockchain network architectures. In singleblockchain systems, forming stake pools might signifcantly increase the blockchain's centralization level, posing serious threats to the network's security. Moreover, in federated-blockchain systems, the transfers of assets among the blockchains within might centralize users to a single blockchain, leaving the other blockchains vulnerable to attacks. Similarly, in sharding-based blockchain networks, the division of the blockchain into shards might weaken the blockchain's security.This thesis develops PoS-based frameworks and proposes solutions for various data management applications to address the abovementioned issues. In the frst study, we develop BlockRoam for roaming management systems, using the PoS consensus mechanism and smart contracts to address roaming fraud. Moreover, an economic model based on the Stackelberg game is proposed to address the stake pool formation's risk. Performance evaluations show that BlockRoam can achieve up to 1100x faster transaction confrmation than Bitcoin and reduce the probability of being attacked by up to 35%.In the second study, we propose FedChain, a framework for federated-blockchain systems with a cross-chain transfer protocol for secure token transfers. In Fedchain, a novel PoS-based consensus mechanism is developed to satisfy strict security re-quirements with improved performance. Moreover, a Stackelberg game model is developed to address the centralization risk. Simulation results show that Fedchain can reduce the transaction confrmation time by up to 23% and improve throughput by 27% compared to static approaches.In the third study, we propose MetaShard, a sharding-based blockchain framework for Metaverse applications. Particularly, we develop a Proof-of-Engagement consensus mechanism to incentivize resource contribution for Metaverse applications. Moreover, to improve the scalability of MetaShard, we propose an innovative sharding management scheme to maximize the network's throughput while protecting the shards from 51% attacks. Numerical experiments show that our approach achieves up to 66.6% higher throughput in less than 1/30 running time and achieves globally optimal solutions in most experiments.These results demonstrate the applicability of the PoS mechanism in data management and the ability of our solutions to address security issues in various types of PoS-based blockchain networks. Potential research directions include Metaverse, Web 3.0, and alternative consensus design to improve the PoS mechanism.