Variety of the large amount and the velocity of the data refer to Big data. Cloud computing is the best approach to store such large volume of data than traditional databases. Maintaining the privacy and access control of big data is the major issue to be considered, in order to avoid the unauthorized user access. Introducing Ciphertext Policy-Attribute Based Encryption (CP-ABE) scheme achieves effective access control of cloud data with less computation overhead in encryption and minimizing pairing operations for less decryption time by having number of attributes in each policy. CP-ABE to be widely used in popular smart terminals that can run social software. Furthermore, existing algorithms for restoring images also have room for improvement in terms of time and space requirements. For this reason, we propose a progressive image restoration strategy based on the improved CP-ABE in this paper. For the improvement of CP-ABE, we design a new encryption scheme to achieve a shorter constant-size ciphertext, construct an auxiliary function to help the independent authority centers generate private keys for users in new ways, design a decryption algorithm with only one bilinear pairing calculation, and provide the update algorithms for attribute revocation. Subsequently, we build a distributed CP-ABE based on our improved CP-ABE, and the correctness and security of the proposed CP-ABE algorithm are also proven.
Volume 12 | Issue 1