Privacy-Preserving Broadcast Remote Signcryption for Edge Computing-Enabled Internet of Medical Things

The integration of edge computing in the Internet of Medical Things (IoMT) offers great potential for decentralized healthcare services but introduces challenges due to the limited computational capabilities of IoMT devices. Ensuring data security and performance is critical, especially when sensitive medical data pass through untrusted edge devices. Traditional cryptographic methods, such as encryption and signing, are impractical for resource-constrained sensors, particularly when securing data for multiple recipients in an anonymous manner. In this paper, we propose an efficient online/offline broadcast remote signcryption scheme to address these challenges. Our scheme enables medical sensors to securely signcrypt data for multiple recipients, ensuring both confidentiality and integrity. It further guarantees that the ciphertext does not disclose the identities of the recipients, thereby preserving their anonymity. It minimizes online computation by offloading resource-intensive tasks to offline processes. This approach enables remote verification without accessing the original data. Implemented within an edge computing framework, the scheme reduces delays in accessing user data while maintaining robust security guarantees. The security of our solution is rigorously proven under the Bilinear Diffie-Hellman assumption, and real-world implementation demonstrates that the scheme is highly efficient, making it well-suited for practical IoMT applications in healthcare.