摘要：Security and privacy issues present a strong barrier for users to adapt to cloud storage systems. In this paper, a new algorithm for data splitting called EPPA is presented to strengthen the confidentiality of data by two-phase process. In EPPA, data object is organized to be several Rubik’s cubes executed for several rounds transformation at the first phase. In every round, chaotic logistic maps generate pseudorandom sequences to cover the plaintext by executing Exclusive-OR operation to form the cipher. Then logistic map is used to create rotation policies to scramble data information based on Rubik’s cube transformation. At the second phase, all cubes are unfolded and combined together as a cross-shaped cube, which will be partitioned into a few data fragments to guarantee that every fragment does not contain continuous bytes. These fragments are stored on randomly chosen servers within cloud environment. Analyses and experiments show that this approach is efficient and useable for the confidentiality of user data in cloud storage system.
