AAQ-PEKS: An Attribute-based Anti-Quantum Public Key Encryption Scheme with Keyword Search for E-healthcare Scenarios

Internet of Medical Things (IoMT) have been utilized in plentiful medical institutions. Nevertheless, since the security of EMRs in IoMT cannot be guaranteed, the EMRs should be encrypted before uploading to cloud server. Public key Encryption with Keyword Search (PEKS) can help the doctors to search encrypted EMRs, but traditional PEKS algorithms cannot resist to quantum computing attacks and without considering access control. To bridge the gap, we propose an attribute-based public key searchable encryption scheme based on lattice, named AAQ-PEKS. Initially, based on the LWE hardness, we first introduce the attribute-based PEKS that can resist quantum attacks for IoMT. Secondly, we combine Attribute-based Encryption (ABE) into AAQ-PEKS to realize access control for sensitive EMRs in the IoMT. Thirdly, the computational security analysis illustrates that our scheme achieves correctness, Indistinguishability against Chosen Plaintext Attack (IND-CPA) and Indistinguishability against Chosen Keyword Attack (IND-CKA). Lastly, comprehensive performance evaluation in practice elaborates that our AAQ-PEKS is more efficient compared with other existing top-tier schemes. To conclude, our scheme has the characteristics of resisting quantum attacks and fine-grained access control for EMR in the IoMT.