Framework for secure data sharing in dynamic group using public cloud

In Cloud computing system data owner stores the data files remotely to utilize the cloud resources. Though data sharing in cloud computing is most common approach used in most communication network because of the different advantages but it also having some difficulties. This scheme involves three general approaches. Treebased Group Diffie-Hellman (TGDH) based group key agreement, proxy re-encryption and proxy signature. The proposed framework tries to reduce the overhead of uploading as well as downloading of the files in the cloud storage. The proxy signature technique is used which allows the group leader to effectively grant the permission to one or more selected group members. The proxy re-encryption is proposed which substitutes most computationally demanding operations to Cloud storage Servers without disclosing any sensitive information or data. The enhanced TGDH scheme permits the group to update the group key pairs using Cloud Servers which does not require all the group members to be online. Proposed scheme provides more efficient, flexible and secured framework for group communication in cloud.