ID-based Signcryption KEM to Multiple Recipients

Identity based signcryption Key encapsulation mechanism (KEM) is used to encapsulate a symmetric key during the construction of hybrid signcryption in the identity based setting. We introduce the notion of Identity based signcryption KEM to multiple recipients (mIDSC-KEM), and define security models for this new primitive. We illustrate by proposing an efficient mIDSCKEM scheme. Our scheme is proved secure in the random oracle model under the Gap bilinear Diffie-Hellman (Gap-BDH) and the Computational Diffie-Hellman (CDH) assumption.