Threshold Attribute-Based Signcryption

In this paper, we propose a new threshold attribute-based signcryption scheme secure in the standard model. The scheme provides message confidentiality, and authenticity of a message in addition to attesting the attributes of the sender. Such a property is useful in applications such as electronic card, digital prescription carrier devices, secure and authentic email service, etc. Our scheme relies on the intractability of the hashed modified decisional Diffie-Hellman and modified computational Diffie-Hellman assumptions, and is proven secure under adaptive chosen ciphertext attack and chosen message attack security notions of signcryption. Further, we achieve a tight reduction for both the security notions in the standard model.