An Efficient Aggregate Signature Scheme With Designated Verifier Based on the Schnorr Signature in Healthcare Wireless Sensor Networks

In healthcare wireless sensor networks (HWSNs), a lot of personal medical data are collected by wireless sensors. Given that a medical diagnostic analysis heavily relies on these medical data, any tampering with medical data may potentially result in severe consequences. So how to efficiently authenticate the collected medical data is a challenging work in such resource-constrained application scenarios. In this paper, we propose an efficient aggregate signature scheme with designated verifier based on the Schnorr signature over an elliptic curve group for HWSNs. In our signature scheme, the set of many individual signatures on very large amounts of collected medical data can be compressed into a concise aggregate signature and their availability can be reduced to the validity of the aggregate signature only believed by a designated verifier. Unauthorized entities cannot trace the origin of these medical data authenticated by the aggregate signature. Meanwhile, our proposed scheme can also stop compressing any invalid individual signature into a valid aggregate signature even if all signers collude. Malicious signers are unable to deny the authenticated data by forging a valid aggregate signature based on several invalid individual signatures. Experimental simulation shows that the computation cost of our provably secure aggregate signature scheme is notably lower than that of existing works.