雲端運算提供了各種服務以及儲存空間給使用者，這也幫助業者減少 管理以及維護儲存伺服器上的成本。但這種新型態的資料儲存服務的興起 也隨之帶來了資料安全上的疑慮，因為使用者無法全權控制儲存在雲端的 資料。目前提出的架構以及方法無法有效率的解決資訊安全上的問題且仍 然存在著其他隱憂。因此本篇論文中首先利用第三認證機制來設計出一個 三方架構以及提出了一套認證方式，再提出了一套加密金鑰管理系統以及 針對系統設計的資料結構來提升整體效率，此外本架構中也利用有效率的 加解密演算法來降低使用者端的運算時間，最後利用模擬以及分析結果來 驗證本架構的安全性以及系統整體效率。;Cloud storage system provides storage to enterprises and end users, and it helps to reduce the cost of server maintenance. Unfortunately, this new type of data storage service also brings new security challenges as data owners do not have full control of their data. The existing research works can not completely resolve these security issues efficiently or may cause other security problems. In this thesis, a framework with the third party auditor is first proposed. Based on our system model, a key management scheme and an authentication process are proposed which can ensure the security of cloud storage. In addition, two types of key loading methods are proposed to improve the performance of key management. In order to create a system with balanced load, AES encryption algorithm is adopted to reduce the computation load on the user side. Through analyses and simulations, we have shown that the proposed system achieves both security and good overall performance.
