遠端檔案系統一直以來是個很重要的研究議題，除了對系統的可靠度和可擴充性等等之外，如何在廣域網路上有效地處理資料更新，也越來越被受到重視。隨著技術的進步，有越來越多的人使用行動裝置，藉著無線區域網路或行動電話數據機與網際網路做溝通。隨著網路的使用量不斷增加，雖然傳輸的能力越來越進步，但是依然無法滿足大多數使用者的需求。
我們提出一個新的檔案存取策略，在傳輸效能無法滿足使用者的情況下，讓使用者能有效率的操作遠端檔案系統中的檔案，減少使用者操作檔案所感受到的延遲；我們並且假設遠端檔案系統的基礎架構是不被信任，所有的資料從客戶端傳送出去，都必須經過加密過程，以保有資料的隱私性。
新的檔案存取策略是基於 Low-bandwidth Network File System (LBFS)的架構。系統中所儲存的單一檔案被分割成數個區塊，當客戶端欲更新資料時，只須加密改變過的區塊，並傳送至遠端機器上，以減少資料傳輸量。
最後，我們利用模擬的方式，在相同的網路環境設定中，藉由更新資料所須的延遲，來評估新的系統與 LBFS 之間的差異。

Remote file system has always been an important research topic. Except for the reliability and scalability of the system, how to efficient process file update in wide area network had been respect for. With the progress of modem technology, more and more people use mobile devices to access Internet by wireless network or cellular modem. Although the ability of transferring data also progress with the trend, it still can not satisfy the needs of most users.
This paper provides a strategy for using remote file system more efficiently in weak network connection. The new protocol reduces the latency of updating files during the users operate files in the system. Furthermore, we assume the infrastructure of the remote file system is untrusted. For the privacy-preserving, all data must be encrypted before they propagate from the client to remote machines.
Our method is based on the Low-bandwidth Network File System (LBFS). A file will be separated into several blocks. When users intend to update the file, the client can just encrypt modified blocks and send them to the server for update.
We evaluated the differences between our protocol and LBFS by simulations on same environment.

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