RPE presentation - Anadi Shakya

Anadi Shakya successfully completed the oral part of her Research Profiency Examination (RPE) on ‘Sieve and Cache: Scalable Access Control for Dynamic IoT Applications’.

Committee Members: Primal Pappachan (Portland State University) ; Dave Maier (Portland State University) ; Wu-chang Feng (Portland State University)

Abstract: The proliferation of smart technologies and newer privacy regulations necessitate effective management of user preferences about data sharing using access control policies. Current Database Management Systems (DBMS) struggle to efficiently answer queries while enforcing a large number of Fine-Grained Access Control (FGAC) policies. Sieve is a middleware for relational DBMSs that generate guarded expressions, which are efficient rewriting of queries with a given set of policies. In this paper, we extend Sieve with caching of guarded expressions to better handle dynamic workloads involving a series of policy insertions and queries at different frequencies. Our novel caching approach includes a replacement policy based on clock algorithm and a refresh strategy based on cost analysis to select between regeneration and update of guarded expressions. We also develop a workload generator that creates different workloads with different distributions of policies, and queries that are relevant to a chosen scenario. These workloads simulate realistic IoT scenarios, such as smart campus applications. Experimental results show that Sieve, enhanced with caching, is effective in terms of cache-hits and efficient in terms of system load and latency of query answering, in dynamic environments.