CARE-EMRs: Efficient and Privacy-Preserving Data Sharing Framework for Electronic Medical Records

Cross-institutional Electronic Medical Records (EMRs) sharing significantly improves healthcare quality and reduces costs. Current EMRs are often stored on cloud servers and protected by Attribute-based Encryption (ABE) for access control. Cross-institutional sharing allows doctors to request EMRs access from target Healthcare Institutions (HIs) through attribute-based collaboration, enabling flexible and secure access. However, existing collaboration in practical EMRs sharing scenarios suffers from inefficiency, hindering timely access and treatment. This paper proposes an efficient and privacy-preserving data sharing framework for EMRs, called CARE-EMRs. CARE-EMRs enables efficient EMRs data access for doctors across different HIs through an outsourcing mechanism. Furthermore, we designed an improved cryptographic primitive PPD-CP-ABE to serve as the security foundation for CARE-EMRs framework, ensuring privacy of the outsourced process. We prove the security of CARE-EMRs. Performance analysis indicates that it significantly reduces the computation and communication overhead.

I. Introduction

Electronic Medical Records (EMRs) are crucial for healthcare diagnosis and treatment. Sharing EMRs enhances healthcare quality and reduces medical costs [1], [2]. To facilitate sharing across Healthcare Institutions (HIs), EMRs are often stored on cloud servers [2]–[4] or blockchain-based systems [5], [6], simultaneously complemented by Ciphertext Policy Attribute-Based Encryption (CP-ABE) to enforce secure EMRs sharing [4], [7], [8]. CP-ABE [9] links users’ private keys to their attributes and enables decryption only if the user’s attributes satisfy the encryption policy. Recently, Attribute-Based Encryption (ABE) with collaborative decryption has been used in EMRs sharing [10]–[13]. These solutions enable users possessing partial attributes set to gain full access rights through attribute-based collaboration. Such collaboration defines that users request translation nodes (attributes specified in the access policy required to collaborate, also the attributes that users lack) from an administrator to complement their existing attributes set, thereby satisfying the access policy. Applying such ABE protocols in cross-institutional EMRs data sharing, doctors can request authorization to access EMRs from target HIs through attribute-based collaboration, thus enabling flexible and secure data access. Despite its benefits, existing attribute-based collaboration in practical EMR sharing faces issues of low retrieval efficiency and heavy computation burden, causing inefficient EMR access. Failure to access and diagnose EMR in a timely manner can be life-threatening, especially in emergencies.