Abstract: Cryptographic techniques for hierarchical access control have attracted intensive research interests recently.There are many differences of the key management schemes in hierarchical access control scenarios.This paper proposes a new key management scheme which can be used for access control in dynamic hierarchies.The scheme can generates and derives hierarchical keys with high performance and can supports the security classes insert and delete in dynamic.The key renewal can be performed with little system spending and the public parameters for each classes is small.