Abstract: Cloud computing provides the efficient use of resources over the internet. In this paper a secure multi owner data sharing scheme for dynamic groups in cloud is proposed. By generating the group signature and encryption technique the user can anonymously store and share the data. When the new user registration is done a group signature is given to the user belonging to a particular group. While downloading the data from the cloud the user has to enter the group signature and secret key which will be received to the user via an e-mail. When both the entities will match then only the user is able to download the data.

Keywords: Multi owner, dynamic broadcast encryption, group signature, user revocation