Supporting Dynamically Changing Authorizations in Pervasive Communication Systems

Abstract

In pervasive computing environments, changes in context may trigger changes in an individual's access permissions. We contend that existing access control frameworks do not provide the fine-grained revocation needed to enforce these changing authorizations. In this paper, we present an authorization framework, in the context of the Gaia OS for active spaces, which integrates context with authorization and provides fine-grained control over the enforcement of dynamically changing permissions using cryptographic mechanisms. Our design, implemented in middleware, addresses the limitations of traditional authorization frameworks and the specific access control needs of pervasive computing environments. As part of our proposed framework, we define cryptographic protocols that enforce access to the system's communication channels and provide secure delivery of messages. We also provide a proof of correctness of key agreement and freshness using the standard BAN deduction system.

Access control using threshold cryptography for ubiquitous computing environments

“…With the event service, users can create secure event channels where channel participants are restricted to authorized entities and sensitive events are encrypted, as described in Lee et al (2005). All relevant sensor components within the smart space infrastructure are connected through a special secure event channel as depicted in Fig.…”

Location constraints in digital rights management

“…The only systems of which we are aware that implement access control of this sort are those of Lee, et al [38] and White, et al [39], which both implement what we will call the "event-based" model. We will consider other methods of enforcement and develop a taxonomy for them in Section 4.…”

“…For example, a process is either permitted to open a file for reading, or it is not; there is no option to control the period of time (for example) for which the file may be open. Access control systems with continuing actions appear to have inspired interest only very recently [27,38,39].…”

“…The systems proposed by Lee, et al [38] and White, et al [39] are examples of event-based systems in which some context manager is able to notify the access control system when an environment condition ceases to be true. For Lee, et al and White, et al, notification is provided by an existing ubiquitous computing network, which may be expensive to implement if it does not exist already.…”

Access Control in Communication Systems

“…Lee et al [2] present an access control architecture that integrates context with authorization and provides fine-grained control over the enforcement of dynamically changing permissions. However, integration with group communication systems (GCS) is not discussed which will be discussed further in Section4.…”