We introduce an efficient signcryption scheme for hybrid authenticated encryption that is provably secure in the standard model under a strong multiuser insider setting. Our new signcryption scheme is built on the basis of a variant of Boneh–Boyen short signature, which works under bilinear groups. The new construction idea is to reuse the signature value to derive the encryption key. This could dramatically save not only the computational cost but also the communication bandwidth. The session key security of the proposed scheme is reduced to a hard problem that is a variant of bilinear decisional Diffie–Hellman problem. Copyright © 2014 John Wiley & Sons, Ltd.