The key update algorithm via HIBE and IKE

In this paper we present a new private key update algorithm based on Hierarchical Identity-Based Encryption (HIBE) where a decryption key can be renewed without having to make changes to its public key. Regarding security, we commence by showing the security of Key-Insulated Encryption (IKE). In addition to this, we propose a three-level encryption model HIBE-IKE by using improved IKE to update the private key in it. The concrete scheme of HIBE-IKE with the demonstration of security is also given in the paper.