Opportunistic Attribute Caching: Improving the Efficiency of ABAC in Fog-Based IoT Networks

The performance of Attribute-Based Access Control is negatively affected by communications over the network between the policy decision point and policy information point for each attribute request. Attribute caching is a standard solution to mitigate this problem. However, due to the dynamic nature of attributes, the cost to keep them refreshed increases for each new attribute replica. This paper presents a method that predicts each request and anticipate the positioning of the attributes closer to the requester exploring the tradeoff between the cost of creating a new replica versus updating a replica. The proposed method follows a two-way approach, where it deals with the current attribute requests and their estimates based on user mobility and the best positions for the attributes. Through trace-driven simulations, considering traces from a large university campus, the method shows a reduction of up to 80% in the number of hops to get the needed attributes at negligible refreshment cost.