ABSTRACT
This chapter starts with the comparison between the public-key infrastructure and the Identity-Based Encryption (IBE). It defines the preliminaries that include the bilinear map and hardness assumptions. The master public key is used by all the users to compute another user’s public key without requiring them to communicate with each other. In order to setup a new user in identity-based encryption, the new user must contact the central authority to retrieve the master public key. In selective-ID model, the adversary commits to a target identity at initialization step before the system is set up. Compared to the security model where the adversary can choose the target identity adaptively, this is a weaker notion of security for identity-based encryption schemes. To make the adversary be forced to output the solution, the challenger should satisfy the adversary’s queries with some quality.
