Gen Kitagata

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We have been working on research and development of advanced network and applications called "flexible computing". We are now in the next stage of this research, strongly pressing forward the concept of flexible computing, namely, "symbiotic computing", towards next generation computing model based on co-existence of real space and digital space. In this(More)
Recently, P2P networks have been evolving rapidly. Efficient authentication of P2P network nodes remains a difficult task. As described herein, we propose an authentication method called Hash-based Distributed Authentication Method (HDAM), which realizes a decentralized efficient mutual authentication mechanism for each pair of nodes in a P2P network. It(More)
IP multicasting is an efficient and scalable way to deliver high quality audio and video streams for group communication. However, widespread deployment of IP multicast is unlikely in near future and it requires substantial infrastructure modifications. For rapid deployment of multicast application, Application Layer Multicast (ALM) is an alternate choice(More)
Recent use of web services has spread over a wide variety of application areas. Users are requested to disclose private information for the use of web services. Such a disclosure is facing the risk of leaking private information. Privacy leakage is becoming one of the serious social problems. For the better use of web services, it is necessary to provide a(More)
In recent years, P2P networks have been evolving at a rapid pace. Authentication of nodes in P2P networks, however, remains a difficult task to conduct efficiently. In this paper, we therefore propose a new authentication method called hash-based distributed authentication method (HDAM). HDAM realizes a decentralized efficient mutual authentication(More)
To reduce the loads imposed on network administrators, we have proposed AIR-NMS, which is a network management support system (NMS) based on Active Information Resource (AIR). In AIR-NMS, various information resources (e.g., state information of a network, practical knowledge of network management) are combined with software agents which have the knowledge(More)
We propose a new knowledge sharing scheme to effectively support networked cooperative works in this paper. Our scheme controls information flow from real space (RS) to digital space (DS) and reverse direction, based on the concept of "symbiotic computing". In practice, our scheme controls the availability of shared workspace in DS for cooperative works,(More)
Access control to resources is one of the most important technologies for supporting human activities in the digital space. To realize the control two schemes were proposed: RBAC (Role-Based Access Control) and TRBAC (Temporal Role-Based Access Control) by adding time constraints and role dependencies to RBAC. However, these methods are not effective for(More)