Efficient key management model and scheme for content access control in hierarchies

Content access control within hierarchies is an ubiquitous problem. It occurs in any context where users have different access rights to a set of resources. Resources are encrypted using cryptographic keys and key management schemes are used to generate, distribute and renew them. We propose a new key management model and build an efficient key management scheme on top of it. We start by introducing the content access control problem and review the most important works on key management for content access control from both multicast and information technology communities. The main contribution of this paper is twofold: first, we propose a key management model that takes advantage of the implicit relations between resources to optimize the number of keys in the hierarchy; second, we propose a key management scheme our model.