Safety Analysis in the NGAC Model

TL;DR

This paper analyzes the computational complexity of safety verification in the NGAC access control model, demonstrating coNP-completeness and providing an improved algorithm that performs well in typical cases despite worst-case scenarios.

Contribution

It establishes the complexity of the safety problem in NGAC and introduces an efficient algorithm for practical safety analysis under realistic assumptions.

Findings

Safety problem is coNP-complete under mild assumptions.

Proposed algorithm outperforms brute force search in typical scenarios.

Real-world mutually exclusive attributes can cause near worst-case performance.

Abstract

We study the safety problem for the next-generation access control (NGAC) model. We show that under mild assumptions it is coNP-complete, and under further realistic assumptions we give an algorithm for the safety problem that significantly outperforms naive brute force search. We also show that real-world examples of mutually exclusive attributes lead to nearly worst-case behavior of our algorithm.