Data Sharing in Cloud Computing Based On Attribute Based Encryption System

A data owner (DO) is usually store large amounts of data in cloud for saving the cost on local data management.Without any data protection mechanism, cloud service provider (CSP), however, can fully gain access to all data of the user.Data owner can fully control the access policy associated with his data which to be shared.However, CP-ABE is limited to a potential security risk that is known as key escrow problem whereby the secret keys of users have to be issued by a trusted key authority.The proposed system revisits the attribute-based data sharing scheme in order to not only to solve the key escrow issue but also to improve the expressiveness of attribute, so that the resulting scheme is friendly to cloud computing applications.The proposed system has an improved two-party key issuing protocol that can guarantee that neither key authority nor cloud service provider can compromise the whole secret key of a user individually.This brings a potential security risk to the user, since CSP may compromise the data for commercial benefits.Ciphertext-policy attribute-based encryption (CP-ABE) has turned to be an important encryption technology to tackle the challenge of secure data sharing.