Cooperation, Trust and Games in Wireless Networks
J. S. Baras and T. Jiang
Symposium on Systems, Control and Networks., Berkeley, CA, June 5-7, 2005
As an important concept in network security, trust is interpreted as a set of relations among agents participating in the network activities. Trust relations are based on the previous behavior of an agent within a protocol. Trust establishment in distributed and resource-constraint networks, such as mobile ad hoc networks (MANETs), sensor networks and ubiquitous computing systems, is much more difficult but more crucial than in traditional hierarchical architectures, such as the Internet and base station- or access point-centered wireless LANs. Generally, this type of distributed networks have neither pre-established infrastructures, nor centralized control servers or trusted third parties (TTP). The trust information or evidence used to evaluate trustworthiness is provided by peers, i.e. the agents that form the network. Furthermore, resources (power, bandwidth, computation etc.) are normally limited because of the wireless and ad hoc environment, so the trust evaluation procedure should only rely on local information. Schemes that depend only on local interaction also have the desired emergent property that enables fast reaction to network member changes, topology changes and security changes that frequently happen in mobile networks. Therefore, the essential and unique properties of trust management in this new paradigm of wireless networking, as opposed to traditional centralized approaches are: uncertainty and incompleteness of trust evidence, trust value is between -1 and 1; locality in trust information exchange; distributed computation.