University of Texas at Arlington
The authors present a new methodology for proving security of encryption systems using what they call dual system encryption. Their techniques result in fully secure Identity-Based Encryption (IBE) and Hierarchical Identity-Based Encryption (HIBE) systems under the simple and established decisional bilinear Diffie-Hellman and decisional linear assumptions. Their IBE system has ciphertexts, private keys, and public parameters each consisting of a constant number of group elements. These results are the first HIBE system and the first IBE system with short parameters under simple assumptions.