BTrust: A New Blockchain-Based Trust Management Protocol for Resource Sharing

The emergence of blockchain technology and cryptocurrencies opened the possibility for building novel peer-to-peer (P2P) resource allocation and sharing models. However, the trustless nature of these P2P models creates the need for reliable and effective trust and reputation mechanisms to minimize the risk of accessing or interacting with malicious peers. Blockchain technology, which is renowned for ensuring trust in trustless environments, provides us with new mechanisms to overcome the weaknesses of the existing reputation and trust management protocols. This paper proposes BTrust, an innovative decentralized and modular trust management system based on blockchain technology for evaluating trust in large-scale P2P networks. To quantify and assess the trustworthiness of peers and identify malicious peers, BTrust introduces a multi-dimensional trust and reputation model to represent trust and reputation scores in a single value derived from multiple parameters with appropriate weightings. Other contributions of this paper include the combination of recommendation and evidence-based approaches into a single system to provide a reliable and versatile way to compute trust in the network, an optimized trustless bootstrapping process to select trustworthy peers among neighbour peers and an incentive mechanism to encourage truthful feedback. We implement and evaluate the BTrust protocol using simulations and show that BTrust is highly resilient to failures and robust against malicious nodes.