SSL-XIoMT: Secure, Scalable, and Lightweight Cross-Domain IoMT Sharing With SSI and ZKP Authentication

The Internet of Medical Things (IoMT) is transforming healthcare by enabling devices to generate and share critical patient data. However, securely sharing this data across different healthcare entities remains a significant challenge due to concerns over privacy and security. Traditional solutions using Ciphertext Policy Attribute-Based Encryption (CP-ABE), Self-Sovereign Identity (SSI), and Zero-Knowledge Proofs (ZKPs) offer secure and anonymous data access, but they often fall short in scalability and integration, particularly in cross domain environments. To address these limitations, we introduce SSL-XIoMT, an optimized SSI and ZKP authentication framework within a consortium Hyperledger-based environment. This innovative system integrates SSI under advanced Zero-Knowledge Scalable Transparent Argument of Knowledge (ZK-STARK) and Plonk protocols within a consortium Hyperledger framework for privacy-preserving identity verification. We enhance identity privacy by integrating Multi-Party Computation (MPC), ensuring that identity credentials and ZKP proofs are securely shared and reconstructed without exposing sensitive information. Additionally, we optimize CP-ABE by offloading complex computations to fog nodes, which pre-compute attributes and logical operations. This approach significantly reduces computational overhead and enhances both privacy and efficiency. Our extensive analysis shows that SSL-XIoMT dramatically improves the performance of processing time for CP-ABE encryption and decryption compared to current methods. Moreover, our hybrid ZKPs based authentication approach outperforms the existing schemes regarding processing time and flexibility. The throughput test also demonstrates that SSL-XIoMT is practical for large scale cross-domain data sharing implementation.