Heterogeneous Signcryption Scheme Based on SM9 and Supporting Equality Test for Wireless Body Area Networks

The rapid development of wireless sensors has accelerated the popularity of wireless body area networks, which use sensors to collect patients' physical data and transmit it to cloud servers for processing and analysis. However, the majority of the cryptographic schemes now in use for wireless body area networks are based on foreign algorithms, which means they do not satisfy the requirements for independent innovation and autonomous information security. This paper proposes a new scheme to address this issue. First, secure communication among users of different cryptographic systems is accomplished based on SM9 in order to provide cloud server confidentiality and authentication. Second, the equality test can realize the retrieval of medical ciphertext and reduce the duplication of medical data. Finally, the online/offline signcryption is adopted to improve the computational efficiency. In random oracle model, the scheme meets the existential unforgeability against adaptive chosen message attack, and is indistinguishable and one-way against adaptive chosen ciphertext attack. Experimental simulation and analysis results show that the scheme is efficient.