Aiming at the problem that most of the current certificateless signcryption schemes in the standard model have low efficiency

this paper proposes an efficient certificateless signcry-ption scheme by reducing the bilinear

and the security of this scheme in standard model has been proved.The result proves that scheme improves the execution efficiency based on not changing the length of ciphertext

and the attractors cannot obtain plaintext information from ciphertext under q-ABDHE problem hypothesi...