Research On Cloud Storage Access Control From Multi-Authority ABE

Cloud computing is developing fast and leading to revolution in internet recently. At the same time, cloud storage is also developing rapid ly. With more application in cloud storage, the higher security is needed. The users need more data security and privacy protection insurance. While providing a flexible fine-grained access control policy is very important, the user can access their data safely and easily.The paper studies attribute based encryption(ABE) scheme, heavy careful concern on attribute weights and multi-authority ABE problems. Then, under the cloud storage application scenarios, we proposed an efficient multi-authority ABE scheme, and e xpanded the scheme by introducing attribute weights to our multi-authority system, enhancing the flexibility of the access structure. Besides, we implemented the algorithm and built a system base on our scheme, taken efficiency test experiments to verify t he flexibility and effectiveness of our scheme. The main work is as follows:1. An efficient multi-authority ABE is proposed. In this scheme, the properties of system divided into multi-subsets and each subset managed by relatively independent attribute agency based on BSW’s CP-ABE scheme. A central authority is used to ensure the correct operation of the system which coordinates the various attribute agencies. Our scheme could avoid some of the problems in single authority, such as authorization server overload operation may appear with the rapid growth of users, there may even cause system failures. Our scheme can not only jointly define a complex ciphertext policy on multiple authorities, but also have the advantage of CP-ABE scheme on each local authority.2. Few existing multi- authority ABE access control schemes consider the attribute weights. We take the concept of attribute weights in our multi-authority scheme. The application scope of the attribute weights is expanded and the system realizes the attribute classification treatment. Consequently the same attribute different weights have different access rights, the expressive power of the access structure is enhanced and access control scheme is more flexible and fine-grained.3. Our scheme is simulated under the windows platform. Theory analysis and experimental results show that the scheme can improve the storage system’s effectiveness and flexibility. A cloud storage ciphertext access control system based on our scheme and OS S SDK is realized. The user’s data confidentiality which is stored in OSS platform can be insured and a fine-grained access control for data sharing is given.