Cloud computing technology is widely used so that the data can be outsourced on cloud can accessed easily. Different members can share that data through different virtual machines but present on single physical machine. But the thing is user don't have physical control over the outsourced data. The need is to share data securely among users. The cloud service provider and users authentication is necessary to make sure no loss or leak of users data. Privacy preserving in cloud is important make sure the users identity is not revealed to everyone.