Efficient identity-based signcryption scheme for multiple receivers
Signcryption is a cryptographic primitive that performs signature and encryption simultaneously. In this paper, we propose an efficient identity based signcryption scheme for multiple receivers which needs only one pairing computation to signcrypt a message for n different receivers and can provide confidentiality and authenticity simultaneously. This scheme turns out to be more efficient than all others proposed so far. We prove its security in the random oracle model. Specifically, we prove its semantic security under the hardness of Bilinear Diffie-Hellman (BDH) problem and its unforgeability under the Computational Diffie-Hellamn (CDH) assumption.