Trust Management in Distributed Systems

Huaizhi Li, Mukesh Singhal
2007 Computer  
Finally, in mobile ad hoc networks-a type of distributed system that has no infrastructure and lets nodes move freely-trust management can mitigate nodes' selfish misbehavior, such as dropping or refusing to forward packets for other nodes to save its battery power while still requiring other nodes' services. Much research exists on trust management 1-3 and reputation management. 4,5 We don't distinguish trust management from reputation management because both can be generalized as dynamic
more » ... g systems. Here, we survey the current research on trust management in distributed systems and explore some open research areas. TRUST MODELS Trust is a complex subject, and no unanimous definition of trust exists. The Merriam-Webster's Dictionary defines trust as "assured reliance on the character, ability, strength, or truth of someone or something." Dictionary.com describes trust as the "firm reliance on the integrity, ability, or character of a person or thing." We define trust as the belief that an entity is capable of acting reliably, dependably, and securely in a particular case. Trust management entails collecting the information necessary to establish a trust relationship and dynamically monitoring and adjusting the existing trust relationship. The various models for describing trust and trust establishment in distributed systems include public-key cryptography, the resurrecting duckling model, and the distributed trust model. Distributed systems such as the Internet, peer-to-peer networks, and mobile ad hoc networks involve numerous entities, many of which haven't previously interacted.Trust management can help minimize risk and ensure the network activity of benign entities in distributed systems. A distributed system is a decentralized network consisting of a collection of autonomous computers that communicate with each other by exchanging messages. These systems are scalable and fault tolerant, and they allow easy resource sharing, concurrent processing, and transparent operation. As the Internet's popularity grows, distributed applications such as e-commerce are becoming important. In addition, with the rapid development of network and communication technologies, new forms of distributed systems-such as peer-to-peer (P2P) networks and mobile ad hoc networks-are quickly emerging. Trust is an important issue in distributed systems. Transactions in distributed systems can cross domains and organizations, and not all domains can be trusted to the same level. Even within the same domain, users' trustworthiness can differ. A flexible and general-purpose trust management system can maintain current and consistent trustworthiness information for the different entities in a distributed system. In e-commerce, for example, a trust-management system lets a buyer and seller become acquainted with each other and estimate the risk of participating in a transaction, thus minimizing the loss. In P2P systems, where each entity acts as both client and server and is expected to contribute to the system, trust management can help reduce free riding, which can seriously degrade P2P system performance.
doi:10.1109/mc.2007.76 fatcat:jwbmkmwyavbt7gnmgn6ydbjbwa