Abstract
Ubiquitous computing is revolutionizing the way humans interact with machines and carry out everyday tasks. It extends everyday computing into the physical world, creating computationally smart environments that feature seamless interactions and automation. As a result of the highly distributed nature of ubiquitous computing, it is essential to develop security mechanisms that lend themselves well to the delicate properties of smart ubiquitous computing environments. In this paper, we introduce a context-aware access control mechanism that utilizes threshold cryptography and multilayer encryption to provide a dynamic and truly distributed method for access control. We simulate our access control scheme and show that access control decisions can be made in a timely manner even as we increase key and file sizes. This mechanism is closely coupled with the context-capturing services and security policy service resulting in a fully context-aware and seamless access control mechanism for typical ubiquitous computing scenarios.