Project Skyfiles, Efficient and Secure Cloud-assisted File Management Application

The Problem:
Nowadays, users store more and more of their songs, pictures and various kinds of files on the cloud due to limited the storage on mobile devices and easy access on the cloud. In order to save storage and bandwidth, these cloud storage services, such as Dropbox, Google Drive, use a shadow file system that only keep meta data of each files like size, date of creation, last modify time and, by default, they do not keep local copies on the smartphones.
However, this feature introduces some issues and limitations of the services. In a shadow file system, due to lacking of local copies, the operation on files are limited. For example, users can not compress or encrypt a file if it does not even exist on the mobile device.

Our Solution:

Motivated by the rapidly development of cloud computing, we persent the Skyfile that utilize the cloud instance to assist the shadow file system to extend its usability.

Particularly, Skyfiles uses Amazon Web Service that 
  • Inexpensive (e.g, a few cents per hour)
  • Could be free (AWS free 750 hrs per mouth for micro instances)
  • Fast computation and network speed
The features of Skyfiles,
  • Use cloud side computation to help file operations.
  • Start / terminate personal cloud instance on-demand.
  • File operations on the cloud instance (compression, encryption, downlaod to cloud, share, etc).
  • File transferred only between cloud storage service and instance

Since the cloud instance is, usually, charge hourly and the operation of Skyfiles only need small amount of time, we introduce Shared Cloud Instances feature that users can share their unexpired instance into a pool and others can use the request the shared instance from the pool. In order to protect users' cloud storage, we use a public-key cryptography algorithm to scurely share the instance.

Publication :

Skyfiles: Efficient and Secure Cloud-assisted File Management for Mobile Devices
[ICC'14] The IEEE International Conference on Communications, Sydney, Australia, June 2014.