Abstract: In order to solve the identify information exposure problem and the decryption unfairness problem in Lal et al’s identity-based multi-receiver signcryption scheme, a novel identity-based multi-receiver signcryption scheme, using the Lagrange interpolation method, was proposed to meet the requirements of the identity anonymity and the decryption fairness. Based on the Bilinear Diffie-Hellman and computational Diffie-Hellman assumptions, the security of IND-sMIBSC-CCA2 and EUF-sMIBSC-CMA was proved formally under the random oracle model, which shows that the proposed scheme can achieve the confidentiality and the unforgeablity required.