Simple and secure mobile access under the flexible organization management

In business we often encounter a situation where two organizations in alliance organize a temporal inter-organizational group to accomplish joint-work. Ideally arbitrary subgroups of these organizations should be able to form a new subgroup with low cost even though these organizations are often run with different subnetwork management policies. In this paper, we propose simple, effortless and transparent mobile communication suitable for the cooperative working environments with protection against the outside attacks. A distinguished property of our approach is that we can achieve our goal without changing the existent router networks. Unlike Mobile IP, our system is more suitable for flexible access control among sub-networks.