Improved Efficiency for CCA-Secure Cryptosystems Built Using Identity-Based Encryption
Recently, Canetti, Halevi, and Katz showed a general method for constructing CCA-secure encryption schemes from identity-based encryption schemes in the standard model. The authors improve the efficiency of their construction, and show two specific instantiations of the resulting scheme which offer the most efficient encryption (and, in one case, key generation) of any CCA-secure encryption scheme to date. In this paper, the authors suggest a new method which allows for the construction of very efficient CCA-secure encryption schemes. The technique modifies the approach of Canetti, Halevi, and Katz, who (as noted above) show a transformation from any semantically-secure "Weak" IBE scheme to a CCA-secure public-key encryption scheme.