Access control in user hierarchy based on elliptic curve cryptosystem

This work proposes a novel key management method based on elliptic curve cryptosystem and one-way hash function to solve dynamic access problems in a user hierarchy. The proposed scheme attempts to derive the secret key of successors efficiently and non-redundantly. It includes functions such as insertion and removal of classes, updating of their relationships, and changing of secret keys. The method utilizes a Central Authority, which enables a user to change the secret key at will conveniently. Since the proposed method uses the elliptic curve cryptosystem which has a low computational cost and small key size, its performance in terms of both security and efficiency is quite commendable. Therefore, it can be anticipated that its use will be extended to wireless communication in the future.