Fähnrich, StefanObreiter, PhilippKönig-Ries, BirgittaDadam, PeterReichert, Manfred2019-10-112019-10-1120043-88579-379-2https://dl.gi.de/handle/20.500.12116/28873In ad hoc networks, there are no incentives to cooperate. There is neither a reward for cooperation nor a punishment for non-cooperation. A distributed reputation system could solve this problem, by giving means of managing trust towards other entities and discovering vicious entities. The existing distributed reputation systems are based on plausibility considerations and, thus, have several limitations. Therefore, in this paper, we aim at overcoming these limitations by proposing the Buddy System as a distributed reputation system that is based on social structure. For this purpose, we choose an appropriate social structure for the Buddy System and discuss the ensuing issues for its maintenance. Finally, we show by the means of simulation the robustness and effectiveness of the Buddy System.enText/Conference Paper1617-5468