A simple way to enforce non-hierarchical access policies

Enforcing non-hierarchical access policies usually requires more complicated key assignment schemes, compared to those schemes used for hierarchical access policies. This paper presents a simple graph translation procedure for the enforcement of non-hierarchical access policies without proposing any new key assignment scheme. The key idea is to transfer a non-hierarchical policy to a hierarchical policy, and then the enforcement can be done by any existing hierarchical key assignment scheme.