Young-Woo Jung

A Secure Group Communication Scheme for Mobile Agents using the Hierarchical Overlay Ring

In multi agent systems, various inter agent communication models have been proposed, and, especially, there are several group communication schemes proposed so far, where some schemes guarantees transparent communication among the agents. However, in mobile agent environments, we require new group communication schemes that consider topology changes caused by mobile agent migrations. Also, these group communication schemes should be secure in order for them to be practical. In this paper, we propose a secure group communication scheme using the hierarchical overlay ring structure of mobile agents. The proposed scheme uses the ring channel in order to cope adaptively with the change of ring topology. The ring channel has basic information for construction of the ring and is managed only by the mobile agent platforms. Therefore, each mobile agent need not directly handle the ring channel and it can perform group communication without any consideration on the change of the ring topology.

On Improving Reliability of E-ODMRP

ABSTRACT In this paper we propose a method which can be used to enhance the reliability of E-ODMRP (Enhanced On-Demand Multicast Routing Protocol). E-ODMRP has low overhead compared to its predecessors since it performs periodic refresh at a rate dynamically adapted to the nodes’ mobility and adopts the local recovery. Upon detecting a broken route, a node performs a local search to graft to the forwarding mesh proactively. However in E-ODMRP there is no packet recovery mechanism. A receiver may lose some packets when it is detached from the multicast tree. We propose a simple packet recovery mechanism that can be incorporated into E-ODMRP for enhanced reliability. We show via simulation that our mechanism effectively enhances the reliability of E-ODMRP.Keywords:Ad Hoc Networks, Multicast, Routing 1. 서 론 1) 모바일 에드혹 네트워크(Mobile Ad hoc networks: MANET)는 네트워크 노드들이 스스로 네트워크를 구성하는 특징이 있어서, 유선 인프라나 중앙 집중 식 장치 없이, 동적으로 네트워크를 구성하는 할 수 있어 단체 컨퍼런스 시, 재난 복구 작업 시에 유용하게 사용될 수 있고 국방 전술망(tactical networks)등과 같이 네트워크 인프라가 없거나 파괴된 곳에서 임무를 수행하는 단체에서 유용하게 사용될 수 있다. 모바일 에드혹 네트워크에서 운영되는 멀티캐스트 프로토

Overlay Ring Based Secure Group Communication Scheme for Mobile Agents

Among the various inter-agent communication models proposed for multi-agent systems so far, several group communication schemes have been issued to guarantee the transparent communication among the agents. However, in mobile agent environments where each agent has mobility in the network, those schemes are not sufficient to fully handle the topological change caused by the migration of mobile agents. Also, these group communication schemes should be secure in order for them to be practical. In this paper, we propose a secure group communication scheme which applies the hierarchical overlay ring structure of mobile agents. The proposed scheme uses the ring channel in order to cope adaptively with the change of ring topology. The ring channel has the fundamental information to construct the ring and is managed by only the mobile agent platforms. Therefore, each mobile agent does not need to directly handle the ring channel and can perform group communication regardless of the changing ring topology.