繼網際網路蓬勃發展後，人們的工作與生活更為便利。雲端運算問世之後，更多企業與個人將雲端運算做資料備份與發佈的平台。企業使用雲端的方式有以下三種：即公有雲、私有雲及混合雲。企業使用公有雲(Public Cloud)將服務與資料儲存交由雲端提供商託管，例如使用Google Docs、G-mail，以減少企業內部的成本。企業亦可建置私有雲(Private Cloud)，以提供檔案備援與內部服務。另外，企業可結合公有雲與私有雲以構成混合雲(Hybrid Cloud)，即使用公有雲儲存敏感度不高之資料並將敏感度較高的資料存至私有雲或本地端。 本研究將探討企業在使用混合雲時遇到的帳號以及檔案內容與授權問題，實作上公有雲應用服務以Google Docs為例、私有雲以Hadoop為例、本地端則以Linux-base電腦為例。本研究使用開放標準OpenID 與O’Auth達到對公有雲的帳號認證、檔案授權，以開發出一個跨本地端電腦或私有雲與公有雲帳號與檔案內容權限之管理與同步系統。本系統可解決在公有雲、私有雲與企業內部系統多重帳號的困擾與企業人員外部存取與內部存取時的權限不足或檔案版本不同的問題。 / Drawing on the rapidly growing Internet technology, people now work and live in a more convenient way. Due to the progress of cloud computing, more and more companies as well as people are using cloud computing as a platform in order to backup and publish data. There are three ways that how enterprises deploy cloud computing: public cloud, private cloud and hybrid cloud. In order to reduce costs, enterprises now days store their data using public cloud and entrust to the public cloud providers, such as using Google Docs, G-mail. Enterprises can also build private clouds to provide files and internal services backup. In addition, enterprises are able to combine public cloud and private cloud into hybrid cloud. We are used to store less sensitive data on the public cloud, while using private cloud or local storage to store highly sensitive data. This study aims to design a system that can solve the problems regarding authentication, file content synchronization and authorization, while enterprises benefit by using hybrid cloud storage. System is designed by taking Google Docs as an example for the public cloud, Hadoop as the example for private cloud, and Linux-base computer as an example for local storage. This research addresses the open standard, namely: “OpenID” and “O’Auth”, in order to solve data content and non-consistency permission between public cloud, private cloud and local hosts.

隨著網際網路的蓬勃發展、雲端運算的興起，各種公有雲端服務林立，企業組織擁有更多不同的選擇與更經濟的解決方案，因此也願意投入更多花費在公有雲上。其中，最重要的一項服務為檔案同步與分享服務(File Synchronization and Sharing, FSS)，其可為企業組織帶來生產力，但在無法完全信任公有雲端服務的情況下，在檔案管理及服務上勢必會採用混合雲部署，私有雲端環境用來處理敏感度較高的資料而敏感度較低的檔案及文件才會採用公有雲端服務。 本研究將探討在混合雲環境下會遇到的使用者多重帳號及身分，以及檔案一致性的問題。我們提出一套整合不同雲端平台帳號的架構和方法，在檔案同步上，設計出三次同步訊息交換和兩階段同步的機制，並且架構出一個入口網站(Portal)服務，根據以上設計架構，實作出一個在混合雲環境，跨本地端、公有雲與私有雲的雲端帳號整合，檔案權限管理與同步之系統，最終可以解決在混合雲環境，不同雲端平台多重帳號的困擾，並可以維持不同裝置和雲端之間檔案資料和權限一致性。本研究最後針對實作出的系統之三大功能模組進行測試，驗證本系統各元件模組的正確性和穩定性，測試結果都是通過的；也針對公、私有雲端，測試檔案同步時間，衡量各種大小檔案同步所需要花費的時間，驗證本系統的效能和實用性。 / As rapid growth of cloud computing and Internet, there are variety public cloud service providers on the market, and enterprises will have more choices and economical IT solutions, therefore, they are willing to spend more on public cloud. Although, the most significant of cloud-based productivity services is file synchronization and sharing, enterprises cannot fully trust public cloud, they will deploy file management system with hybrid cloud which they store less sensitive data on public cloud and highly sensitive data on private cloud. This study aim to design a system on hybrid cloud deployment that can solve the problems regarding too many online accounts and synchronize data and permissions between different devices and cloud to maintain consistency. We propose a method to integrate accounts on different cloud and design a mechanize of file synchronization which contains three steps messages flows and two stages synchronization to implement the system, otherwise, we also create a portal service. Last but not least, we test three main modules of the system to verify correctness and stability and the results are all pass. Also, we measure the synchronization time of files with different size to verify effectiveness and practicality.

Commercial provisioning of file synchronization services (FSS) relies entirely on protocols that utilize a remote central server that is often located in the cloud to host important files. Updates at user computers are propagated to the central server and from the central server to other sources in need of such updates. Therefore, a synchronization operation between two computers located on the same network often results in file data transmission to and from this local network at least twice. This introduces an unnecessary bandwidth usage on a user’s local network and has become an issue, especially since there is an increase in the demands for internet resources. This thesis work presents a new file synchronization protocol towards FSS known as LAPSync (location-aware protocol for remote file synchronization). This paper also proposes a hierarchical synchronization mechanism by utilizing LAPSync. Our proposed solution relies on the ability of LAPSync clients to acquire knowledge about the location of clients participating in the synchronization operation to construct a hierarchical synchronization path. Finally, we implement our protocol into a prototype and conduct experiments to compare with drop-box (a popular file synchronization service). The results obtained show that LAPSync offers a reduction in bandwidth usage when the files to be synchronized exist on the same local network

Cloud storage services allow users to store and access data in a secure and flexible manner. In recent years, cloud storage services have seen rapid growth in popularity as well as in technological progress and hundreds of millions of users use these services to store thousands of petabytes of data. Additionally, the synchronization of data that is essential for these types of services stands for a significant amount of the total internet traffic. In this thesis, seven cloud storage applications were tested under controlled experiments during the synchronization process to determine feature support and measure performance metrics. Special focus was put on comparing applications that perform client side encryption of user data to applicationsthat do not. The results show a great variation in feature support and performance between the different applications and that client side encryption introduces some limitations to other features but that it does not necessarily impact performance negatively. The results provide insights and enhances the understanding of the advantages and disadvantages that come with certain design choices of cloud storage applications. These insights will help future technological development of cloud storage services.