Energy Efficiency in Secure and Dynamic Cloud Storage

The popularity of the cloud storage systems has brought a number of challenges. Two of them are data integrity and energy efficiency. There are many proposed static solutions to prove the integrity of a file. For the dynamic case, Rank-Based Authenticated Skip list (RBASL) has been presented. It provides the update operations with logarithmic complexity. However, an RBASL expects the block size to be fixed. In a realistic scenario, where the updates can be of variable size, an RBASL performs O(n) update operations on the data structure when a change in the file occurs, where n is the number of blocks. To overcome this problem, we propose Flexible-length based authenticated skip list (FlexList) to make O(u) update operations where u is the number of the update operations. Moreover, we developed an algorithm to carry out multiple challenges at once. We have tested our algorithm, and the results show time and energy efficiencies of 60%, 45%, 35% and 20% for file sizes 4MB, 40MB, 400MB, and 4GB respectively.