Certificateless signcryption scheme in standard model

Most of the current identity-based signature schemes are secure in the random oracle model but many of them have security problem.In this paper an efficient and provably secure identity-based certificateless signcryption scheme was proposed.The scheme was proved secue in the standard model and reduced the q-Augmented Bilinear Diffie-Hellman Exponent q-ABDHE problem.Compared with the known identity-based scheme in the standard model the proposed scheme has shorter signature length and less operation.