Research On Transaction Scheme Based On Blockchain

For decades,the development of the Internet continuously improves the growth and transformation of e-commerce.As the main content of e-commerce,promoting secure online transactions worldwide is always the core of building large-scale transaction systems on the Internet.In the existing transaction system,the system operator centrally facilitates transactions between traders.The centralized system architecture is a common mode of traditional trading systems,but there are some security risks.For example,centralized systems are less resistant to attacks on infrastructure facilities.Blockchain technology has the characteristics of decentralization,openness,transparency,and tamper resistance,which can alleviate the single point of failure in the centralized transaction system and handle its security issues properly.Therefore,this thesis combines related cryptographic technologies to construct two blockchain-based distributed transaction systems.One is to use cryptocurrencies to trade products on blockchains,that is,a blockchain-based transaction system;the other is trading cryptocurrencies between different blockchains,namely cryptocurrency exchanges.Specifically,the main work of this thesis is as follows:· For cryptocurrency exchanges,we propose an atomic cross-chain trading scheme.In this research work,we introduce external mediators to passively escrow the trader's cryptocurrency and only mediate when there is a dispute between traders,ensuring the atomicity of the transaction.We design a fair secret sharing scheme to distribute mediation rights among multiple mediators fairly and securely,which mitigates the impact of a single mediator's denial of service.We design a verifiable encryption scheme for a commitment to eliminate order dependence in transaction creation and maintain high efficiency and low cost without sacrificing atomicity.By combining the above schemes,we propose an atomic cross-chain trading scheme, which does not rely on complex cross-chain verification technology and therefore can be better compatible with the existing blockchain.· For the blockchain-based transaction system,we propose a blockchain-based transaction system for physical products.In this research work,we design an efficient smart-contract-based product publishing module to make it independent of a central platform and well scalable with low monetary costs.We present a blockchain-based fair payment module to ensure that any entity's misbehavior could not compromise the security.We propose a blockchain-based product traceability module to ensure the authenticity and traceability of physical products.We integrate all these modules into one system,dubbed PBOT,which is a blockchain-based transaction system for physical product trading with fairness,privacy preservation,and auditability.Our implementation of its core modules and comprehensive performance evaluation demonstrates its feasibility and high efficiency.