Data Access Control Schemes For Cloud Computing

As the combination of computer and internet technology, cloud computing has not only been areform in the IT but also a great revolution in the IT business model. The application of the cloudcomputing has narrowed the gap between big businesses and minor enterprises to such an extentthat top information technology and service are accessible to almost everyone, with extremely lowcosts. This innovated computing and business model will bring about unprecedented profoundchange to the information industry.With the more application of the cloud computing, its security has been drawing more attentionfrom the industry. However, compared with its application, the development of the security of thecloud computing is relatively slow. Unreliable cloud computing service provider has become amajor threat among those to the security of the cloud computing.To solve the security problem, this thesis uses CP-ABE encryption algorithms to establishaccess control model which applies to the cloud computing. This approach, making use of AESsymmetric and CP-ABE encryption algorithms, encrypts both data and symmetric key so that usersby matched attributes can decrypt the key and data cipher texts one by one. To reduce overhead ofstoring and updating keys, our approach introduces the keys distribute centers to mange the attributeand keys.The cloud computing service provider cannot decrypt the data, because it has no keys.Then, we analyze the security and computation, and implement the algorithm under Ubuntu.Weprove that our approach has certain feasibility.