Efficient Cryptographic Protocol Design for Secure Sharing of Personal Health Records in the Cloud

The sharing of Personal Health Records (PHR) in the cloud is the most promising platform to exchange health-related information. However, personal medical and health information storage is outsourced to third parties, potentially exposing patients' privacy to unauthorized individuals or groups. This paper intends to propose a new SSPHR (Secure Sharing PHR) method in the cloud. The proposed SSPHR method can preserve the privacy of PHRs and also ensures patient-centric control on PHRs. The encrypted PHRs are stored on the untrusted cloud servers and it grants selective access to different users on different PHRs portions. In addition, a semi-trusted proxy known as Setup and Re-encryption Server (SRS) is presented to arrange the public/private key pairs and to generate the re-encryption keys. This paper introduces a new Modified El-Gamal encryption for preserving health records and it includes key generation, encryption, and decryption process. Finally, the proposed model performance is compared and proven against other existing methods.