Implement Efficient Data Integrity for Cloud Distributed File System Using Merkle Hash Tree

There are various cloud distributed file systems have been proposed in recent years. The users are able to obtain the vast cloud storage spaces through Internet access even if the essence of storage space in portable devices and handsets are restricted and insufficient. In this work, we implement a distributed file system based on an open source named Apache Hadoop, and the original Hadoop file system is replaced with the Tahoe least-authority file system. Furthermore, we investigate the data block size of Merkle hash tree in Tahoe file system, and experiment the total transmission rate and download time with two different file sizes. The experiment result shows that the file system provides a secure and reliable cloud storage service even if parts of storage nodes are broken, and the suggestible block size is found.