Improving Indirect Key Management Scheme of Access Hierarchies

This paper examines possible modifications to indirect key management schemes that may improve their performance and efficiency for use within access hierarchies. A new method is proposed which uses a dedicated HMAC construction as the key transformation function, a new addressing strategy to improve accessibility verification, and a cached key update strategy which seeks to minimize key updates in large environments when immediate changes to the hierarchy are required. The proposed method can be applied to simple access hierarchies, and a modification is proposed which allows more complex access hierarchies to be addressed.