Analysis of a Hybrid Reputation Management System for Mobile Ad hoc Networks

In cooperative systems such as wireless ad hoc networks, tasks are conducted based on the cooperation of nodes in the system. However, selfish nodes may refuse to be cooperative. Reputation system and price-based system are two main solutions to this problem. In this paper, we use game theory to investigate the underlying cooperation incentives of both systems. We found that the strategies of using a threshold to determine the trustworthiness of a node in the reputation system and of rewarding cooperative nodes in the price-based system may be manipulated by clever selfish nodes to gain benefits while still being selfish. Illumined by the investigation results, an integrated system is proposed and studied. Theoretical and simulation results show the superiority of the integrated system over individual reputation system and price-based system in terms of the effectiveness of cooperation incentives. offers forwarding service. Game theory (12) is a theory of applied mathematics that models and analyzes the interactive decision situations. In this paper, we use game theory to model and study the individual reputation system and price-based system, and analyze their underlying incentives and inherent deficiencies. We found that the incentives of both systems can encourage nodes to be coop- erative to a certain extend. The strategies of using a threshold to determine the trustworthiness of a node in the reputation system and the strategies of rewarding cooperative nodes in the price-based system may be manipulated by clever selfish nodes to gain benefits while still being selfish. In addition, we also propose an integrated system combining reputation system and price-based system. The integrated system leverages the advantages of both systems and overcomes their individual disadvantages, making the potential reciprocity the focal point of integration. We build a game theory model for analyzing the integrated system. The remainder of this paper is organized as follows. Sec- tion II provides relative works. Section III presents the analysis based on game theory for individual reputation systems price- based systems and the proposed integrated system. Section IV presents the simulation results. Section V concludes the paper.