Provably Secure (Broadcast) Homomorphic Signcryption

Signcryption has drawn a lot of attention due to its useful applications in many areas, in particular for applications where the computation and communication resources are constrained, for example, for lightweight devices. The traditional signcryption scheme does not support the homomorphic property. Recent work by Rezaeibagha et al. (Provsec 2017) offered a provably secure homomorphic signcryption scheme, in which for the first time, provided a scheme provably secure under some restriction. In this paper, we show that the homomorphic signcryption can be extended to provably secure broadcast signcryption scheme. We allow the broadcasted signcrypted data items to be aggregated without requiring decryption that is a desirable feature in distributed environments.