
104 ◾ Secure Data Provenance and Inference Control
Distributed reasoning. A solution that we implemented for handling the memory
constraint problem was to partition the knowledge base (Cadenhead et al. 2010).
At first this appeared as a very naive solution; arbitrary partitioning would not
return the same answers to an access control query as that obtained by querying
one knowledge base in memory. An access control query is formulated to answer
questions like: Does Kelly currently have access to Bob’s record? What is the dura-
tion of such access? Is there a conflict between two roles? After examining the
current model for RBAC, we apply the ba ...