Searchable Public-Key Encryption with Data Sharing in Dynamic Groups for Mobile Cloud Storage

Mobile cloud computing is referred as the combination of cloud computing and mobile networks to bring benefits for both mobile users and cloud computing providers. While once the data of mobile users is outsourced to the cloud, it is a formidable and challenging task for the data owners to realize both the data confidentiality and the utilization because it seems unachievable to search and retrieve the special contents on the data encrypted by traditional encryption schemes. To address this issue, we propose a searchable public-key encryption scheme for a group of users in mobile cloud storage. In our proposal, a dynamic asymmetric group key agreement protocol is utilized for data sharing among a body of mobile users and the technique of proxy re-signature is employed to update the searchable ciphertexts when the mobile users in the group varies. Through the security proof and performance evaluation, we demonstrate the new scheme is both secure and efficient, and hence it reaches the requirements of the users, network operators, as well as cloud computing providers in application.