Benchmarking UAQ Solvers

The User Authorization Query (UAQ) Problem is key for RBAC systems that aim to offer permission level user-system interaction, where the system automatically determines the roles to activate in order to enable the requested permissions. Finding a solution to a UAQ problem amounts to determining an optimum set of roles to activate in a given session so to obtain some permissions while satisfying a collection of authorization constraints, most notably Dynamic Mutually-Exclusive Roles (DMER) constraints. Although the UAQ Problem is NP-hard, a number of techniques to solve the UAQ problem have been put forward along with encouraging, albeit inconclusive, experimental results. We propose a methodology for designing parametric benchmarks for the UAQ problem and make a novel suite of parametric benchmarks publicly available that allows for the systematic assessment of UAQ solvers over a number of relevant dimensions. By running three prominent UAQ solvers against our benchmarks, we provide a very comprehensive analysis showing (i) the shortcomings of currently available benchmarks, (ii) the adequacy of the proposed methodology and (iii) that the reduction to PMaxSAT is currently the most effective approach to tackling the UAQ problem.