|Speaker:||Dr. R. K. Shyamasundar|
|When:||Friday, June 30, 2017, 11:00am - 12:00pm|
|Where:||Research Hall, Suite 417|
Information flow control (IFC) models supporting discretionary access control (DAC) features are becoming a necessity in building decentralized secure systems. In this paper, we propose a novel IFC model called Readers-Writers Flow Model (RWFM) using explicit readers and writers that provides a label model for capturing relationships and constraints of information flow among the stakeholders. RWFM provides an application independent concrete generative label model that is sound and complete with respect to Denning's Model. We define the semantics of information flow including downgrading in this label model, and argue that reading and writing induce possibly different pre-orders on the set of subjects of the information system. Hence, the subject relations become explicit making it possible to derive the relations from the labels. We further define a notion of "information dominance" on subjects and show that the notion of principal hierarchy, as used in the discretionary setting, does not mix well with IFC. Our proposed model, integrates with IFC the needed discretionary policies consistent with the underlying mandatory access controls (MAC) of the flow model. We demonstrate various succinct applications of our approach to practical end-to-end scenarios, and briefly discuss the potential of the RWFM B1-secure operating systems and language based security.
Dr. R. K. Shyamasundar is a Professor in the Department of Computer Science and Engineering at Indian Institute of Technology, Bombay, India.