Abstract: Signcryption can combine both the functions of digital signature and public key encryption in a logical cryptography protocol, at lower computational costs and communication. A new efficient identity-based signcryption scheme was proposed by characteristics of bilinear map of elliptic curve. This scheme can satisfy the confidentiality, unforgeability and forward security required by signcryption.What's more, the scheme is secure against dishonest recipient. This scheme is also very efficient and secure after analyzing and being compared with other schemes.