Secure Cloud Storage

Abstract

The rapid growth of Cloud based services on the Internet invited many critical security attacks. Consumers and corporations who use the Cloud to store their data encounter a difficult trade-off of accepting and bearing the security, reliability, and privacy risks as well as costs in order to reap the benefits of Cloud storage. The primary goal of this thesis is to resolve this trade-off while minimizing total costs.

This thesis presents a system framework that solves this problem by using erasure codes to add redundancy and security to users’ data, and by optimally choosing Cloud storage providers to minimize risks and total storage costs. Detailed comparative analysis of the security and algorithmic properties of 7 different erasure codes is presented, showing codes with better data security comes with a higher cost in computational time complexity. The codes which granted the highest configuration flexibility bested their peers, as the flexibility directly corresponded to the level of customizability for data security and storage costs. In-depth analysis of the risks, benefits, and costs of Cloud storage is presented, and analyzed to provide cost-based and security-based optimal selection criteria for choosing appropriate Cloud storage providers. A brief historical introduction to Cloud Computing and security principles is provided as well for those unfamiliar with the field.

The analysis results show that the framework can resolve the trade-off problem by mitigating and eliminating the risks while preserving and enhancing the benefits of using Cloud storage. However, it requires higher total storage space due to the redundancy added by the erasure codes. The storage provider selection criteria will minimize the total storage costs even with the added redundancies, and minimize risks.