Shigetoshi Yokoyama

An Anonymous Context Aware Access Control Architecture For Ubiquitous Services

A new context aware access control architecture called Anonymous Context Aware Access Control Architecture (ACA2) is proposed. The basic idea of this architecture is based on an analogy to the public telephone service. Anonymous users can use services supported by their context information through preregistered software components called proxies. The main features of the architecture include anonymity, access suspension caused by context changes, and active context certificates with stream verification.

An Asynchronous Messaging Platform for Development of Context-aware Services

The design for an asynchronous messaging platform is proposed as an aid in developing context-aware services in a network environment having a ubiquitous presence of information publishers that actively issue information and information holders that provide information on request. Context-aware services use the result of analyzing context based on multiple sources of information as an execution trigger. This platform can calculate and provide the execution triggers to application logic. It can accomplish this in a distributed environment without destroying the order in which asynchronous information is generated and even by using information obtained through synchronous inquiries. The design of this platform takes a large-scale, distributed scenario into account making it adaptive to a ubiquitous computing environment. The authors show by preliminary performance measurements that the platform is robust to an increasing number of participating nodes and messages