Forward-Secure Identity-Based Encryption Scheme

To deal with the threat of key exposure, an identity-based encryption scheme with non-interactive key update is proposed. The non-interactive property is obtained by forward-security (a typical key evolving paradigm). First the definition and security definition of Identity-Based Encryption with Non-Interactive Key Update scheme (IBE-NIKU) are given. Then identity-based binary tree encryption scheme is constructed. As a result, a concrete IBE-NIKU is given. The security and efficiency of these schemes are also analyzed.