Abstract: This paper proposes a brocasting algorithm based on identity encrpytion scheme named as IBESB.Firstly, we introduce the preconditions of the algorithm proof, then IBESB is described in details. The security and integrity on choosing ciphertext in random oracle model are proved based on BDH assumption. Compared with traditional brodcasting algorithms, IBESB outstands them both in computing complexity and memory cost.