Efficient and provably secure certificateless signcryption from bilinear pairings

Certificateless cryptography aims at combining the advantages of identity based and traditional certificate-based public key cryptography, so as to avoid the key escrow problem inherent in the identity based system and certificate management in public key infrastructure. Signcryption is an efficient cryptographic primitive which achieves confidentiality and authentication simultaneously in a logical algorithm. In this paper, we propose an efficient certificateless signcryption scheme and prove it secure in the random oracle model which guarantees confidentiality and authenticity. Furthermore, our scheme does not require pairing to signcrypt a message and only needs to compute two pairings in the designcrypt stage, it is more efficiently than the previous schemes. © 2010 Binary Information Press.