Security applications of trust in multi-agent systems

Abstract

The concept of trust as presented here focuses on the trustworthiness, or reliability, of information and information sources. Decision makers, or agents, can create judgments based on previous experience with other agents and by reputation information received from allied agents. These judgments, or trust assessments, are used to predict the behavior of other agents and analyze the trustworthiness, truthfulness, or quality of information. Research concepts have been developed within the trust community, and they are most commonly applied to multi-agent systems research. This work attempts to show that trust research can be directly applied to security problems. Modern trust concepts enforce soft security which can be applied in addition to conventional security methods to build a more robust secure system. This article examines two trust based techniques and demonstrates their basic effectiveness using empirical experimentation. These techniques are then applied in a case study drawn from a more robust domain concerning confidential message transmission. The benefits of applying trust-based techniques to secure a system are measurable, and the costs associated with such techniques are scalable to even the most resource constrained systems. Security applications of trust in multi-agent systems are human users, applications or systems. This online monitoring allows the identification of suspicious patterns and malicious or negligent intent. These trust-based processes can enrich the security of systems when combined with traditional security measures. The contribution of this work is the definition of trust as it relates to security problems and the demonstration of how it can be applied in several different ways.Supporting this concept, security expert Bruce Schneier has explained that security is not a product; it is a process [27]. Trust is certainly not a suitable replacement for existing security mechanisms in many cases, but the strengths of trust directly complement those of conventional security. By combining the strengths of trust research with those of conventional security methods, new security mechanisms can be developed that are flexible enough to accommodate unexpected system attacks.Trust is a current research field within the general arena of multi-agent systems. Software agents are self contained, autonomous, intelligent, proactive and goal driven entities [7]. Agents are well suited for and extensively used in many industrial and commercial applications. Some examples include: electronic commerce and e-markets, real time monitoring of telecommunication networks, improving traffic flow, automated scheduling, optimizing industrial processes and simulating complex social processes. One common theme among these applications is inherent distribution, meaning that information is distributed spatially, temporally, semantically and functionally. Another common theme is inherent complexity, meaning these problems are typically too large or impractical to solve using a single centralized system [32]. Becau...