GuRuChain: Guarantee and Reputation-based Blockchain Service Trading Platform.

Blockchain (BC) is a promising Distributed Ledger Technology (DLT) that has attracted attention in recent years due to its characteristics of maintaining privacy and security. This technology, which removes the need for a trusted third party, can be applied in various trust-related domains, such as energy trading, crowdsourcing, and the Internet of Things. This paper presents GuRuChain, a platform framework for online service trading. It combines on-chain and off-chain trust management to provide a blockchain system suitable for trust-related applications. The platform does not only ensure the recording of online transactions; but also the deliverance of offline services. In GuRuChain, we propose a mathematical model to assess the trustworthiness of each participant. We also introduce an incentive mechanism based on reputation and guarantee to monitor the participants' behavior. Finally, we maintain the consistency of the BC through the proposed consensus scheme called Proof Guarantee and Reputation (PoGR). PoGR selects nodes based on a scoring formula that uses three parameters, reputation score, guarantee balance, and risk taken to ensure fairness. The results of the performance evaluation demonstrate the feasibility, efficiency, and scalability of GuRuChain.