Revocable Identity-Based Matchmaking Encryption with Equality Test for Smart Healthcare

Smart healthcare establishes a safe, reliable, and efficient medical information system for the public with the help of the Internet of Things, cloud storage, and other Internet technologies. To enable secure data sharing and case-matching functions in smart healthcare, we construct a revocable identity-based matchmaking encryption with an equality test (RIBME-ET) scheme for smart healthcare. Our scheme not only ensures the confidentiality and authenticity of messages and protects the privacy of users, but also enables a cloud server to perform equality tests on encrypted ciphertexts from different identities to determine whether they contain the same plaintext and protects the confidentiality of data in the system through a user revocation mechanism. Compared with the existing identity-based encryption with equality test (IBEET) and identity-based matchmaking encryption with equality test (IBME-ET) schemes, we have improved the efficiency of the scheme and reduced communication overhead. In addition, the scheme's security is proven in the random oracle model under the computational bilinear Diffie-Hellman (CBDH) assumption. Finally, the feasibility and effectiveness of the proposed scheme are verified by performance analysis.