ATTRIBUTE BASED DATA SHARING IN CLOUD COMPUTING

Abstract

In cloud computing secure data sharing can be done through very promising encryption technique which is known asCiphertext-policyattribute-basedencryption(CP-ABE).Inthis scheme the access policy related to the data to be shared is controlled by the owner of the data . There isa securityriskknownaskeyescrowproblem intheCP-ABEschemebecause a trusted key authorityisresponsiblefortheissuingofthesecretkeysofusers.Attributewith arbitrary state are not supported by most of the CP-ABE schemes which are already existing.This thesis aim at the removal of key escrow issuefromattribute-baseddatasharing scheme and improvement of the expressiveness of attribute. So to ensure that the whole secret key of a user can’t get compromisedbycloudserviceproviderorby keyauthoritythe proposal of an improved two-party key issuing protocol is given. In addition, we present the idea of attribute with weight, being given to improve the outflow of attribute, which can not just stretch out the articulation from binary to arbitrary state, yet in addition help to lighten the complexity of access policy. Improvement regarding complexity ofciphertextencryptionandstoragecostaredone in this scheme. The performance analysis and the securityproofsareprovidedwhichimplies that efficient and secure data sharing is achieved by this scheme.