A Dynamic Secure Group Sharing in Cloud Computing

Cloud computing is the long dreamed vision of computing as a utility, where data owners can remotely store their data. The basic service provided by the Cloud is Data Storage. However, it is a difficult task for sharing data in multi-owner manner where group admin and all group members can store and modify data while preserving data and identity privacy from an untrusted cloud server, due to the frequent change of the membership. Therefore secure multi-owner data sharing scheme for dynamic groups in the cloud computing have been proposed which involve integration of group signature and broadcast encryption techniques. But this system also identified some limitations in terms of efficiency and security. Because multi-owner data storing and sharing in a dynamic environment dumps huge amount of data files in the cloud, which remains in cloud for indefinite period of time. The sensitive information stored may misused by service providers. To maintain cloud files security and privacy regular removal of unwanted files is needed. To resolve this drawback we propose new framework for MONA that remove unwanted files automatically when the predefined time period for sharing specified by data owner has been expired which improve performance of the system in terms of security and efficiency. Also this mechanism reduces the overhead during upload and download file in the cloud. Finally proposed method MODOC claims required efficiency and most importantly security. We implement a working prototype of the MODOC methodology and evaluate its performance based on the time consumed during various operations The results show that MODOC has the potential to be effectively used for secure data sharing in the cloud.