Achieving Forward Secrecy and Unlinkability in Cloud-Based Personal Health Record System

This paper proposes a symmetric key based PHRMS solution for cloud satisfying the following security and privacy properties: (1) forward data secrecy i.e., a user (for example, a doctor) with old keys cannot access any newly added data, (2) data unlinkability i.e., no unauthorized user can link an outsourced PHR information to its owner, and (3) write integrity protection i.e., no unauthorized user can modify the outsourced PHR data including their actual writers (for example, a doctor or Laboratory), even if they collude with the cloud service provider.