Attribute-Based Ring Signcryption Scheme and Its Application in Wireless Body Area Networks

Wireless body area network WBAN technology has attracted intensive attention from the academic and industrial research communities in recent years. For widespread deployment of WBANs, security and privacy must be addressed properly. In this paper, we introduce a new cryptographic primitive named key-policy attribute-based ring signcryption KP-ABRSC scheme, which is a combination of identity-based ring signature scheme and key-policy attribute-based encryption scheme. In KP-ABRSC, each signcrypted message is labeled by the sender with a set of descriptive attributes and a list of identities of potential senders, while an access structure is embedded in each user's private key by a trusted authority. We give formal syntax and security definitions for KP-ABRSC scheme and construct a KP-ABRSC scheme from bilinear pairings. The proposed KP-ABRSC scheme is proven to be indistinguishable against adaptive chosen plaintext attacks under the DBDH assumption and existentially unforgeable against adaptive chosen message and identity attacks under the CDH assumption. Finally, we present a cloud-based healthcare framework by exploiting our proposed KP-ABRSC scheme and WBANs, which can ensure data authenticity, confidentiality and non-repudiation, but also can offer participants privacy and fine-grained access control on encrypted medical data.