Audit-Free-Cloud-Storage-via-irrefutable-Attribute-based-Encryption

Abstract

Cloud storage services have grow popularly. For the importance reason of privacy, many cloud storage encryption schemas has been proposed to secure the data from those who do not have access. All such schemes assume that cloud storage providers are secure and cannot be hacked. However in practice, some authorities may compel cloud storage providers to make public user secrets and confidential data. We consider the problem of building a secure cloud storage service on top of a public cloud infrastructure where the service provider is not completely trusted by the customer. In this paper a new cloud storage encryption schema is proposed which allows cloud storage providers to protect user privacy. Since authorities cannot tell the obtained secrets are true or false, the cloud storage providers ensure that the user privacy is still securely provided. The proposed schemes believe cloud storage service providers or trusted third parties handling key management are trusted and cannot be hacked. Some times may intercept the communication between users and cloud storage providers and then compel storage providers to release user secrets by using government power or other means. In this case the encrypted data are assumed to be known and storage providers are requested to release user secrets. The proposed Deniable CP-ABE scheme is to build an Audit free cloud storage service. The deniability feature makes coercion invalid, and the ABE property ensures secure cloud data sharing with a fine grained access controlled mechanism.