Cloud-based Encrypted EHR System with Semantically Rich Access Control and Searchable Encryption

Redwan Walid, Karuna P. Joshi, Seung Geol Choi, Dae-young Kim

Abstract: Cloud-based electronic health records (EHR) systems provide important security controls by encrypting patient data. However, these records cannot be queried without decrypting the entire record. This incurs a huge amount of burden in network bandwidth and the client-side computation. As the volume of cloud-based EHRs reaches Big Data levels, it is essential to search over these encrypted patient records without decrypting them to ensure that the medical caregivers can efficiently access the EHRs. This is especially critical if the caregivers have access to only certain sections of the patient EHR and should not decrypt the whole record. In this paper, we present our novel approach that facilitates searchable encryption of large EHR systems using Attribute-based Encryption (ABE) and multi-keyword search techniques. Our framework outsources key search features to the cloud side. This way, our system can perform keyword searches on encrypted data with significantly reduced costs of network bandwidth and client-side computation.