Abstract
Cloud computing is associate raising computing paradigm within which resources of the computing infrastructure are provided as services over the web. As promising because it is, this paradigm conjointly brings forth several new challenges for information security and access management once users source sensitive information for sharing on cloud servers, that aren't at intervals an equivalent trusted domain as information homeowners. To stay sensitive user information confidential against un-trusted servers, existing solutions typically apply cryptographically ways by revealing information decoding keys only to approved users. However, in doing therefore, these solutions inevitably introduce a significant computation overhead on the information owner for key distribution and information management once fine-grained data access management is desired, and therefore don't scale well.