An Improved CCA-secure PKE from Identity-Based Techniques

Abstract

In this paper, a public key encryption (PKE) scheme of Lai et al. [13], presented in CT-RSA 2010, is analyzed at first. Then we show that the scheme is not a IND-CCA (In distinguish ability against adaptive chosen cipher text attack) secure PKE scheme. Then an improved PKE from identity-based techniques is proposed and we prove its IND-CCA security in the standard model. The improved scheme needs shorter public key and shorter cipher text than the scheme of Lai et al., and it is as efficient as the later scheme in the processes of encryption and decryption.