Abstract
In recent years, with the rapid development of cloud storage, many popular cloud storage service providers have been introduced. For example, the number of Dropbox users has risen to over one hundred and seventy-fi ve million since 2007. By using this kind of service, users no longer need to take their data with them anytime. It is also increasingly easy to synchronize files across local devices and remote clouds. But because each of the providers provides their own application individually, it is an inconvenience for users to use their storage services at the same time across different providers. The other issues of these services is privacy and security. Most of the cloud storages belong to "public" cloud storage. It means that the storages are managed by the providers instead of the users. Although these providers claim that they do not access users' data anyway, many users still worry about the privacy and potential security problems. To solve these problems above, we proposed the architecture for integrating multiple cloud storages and synchronizing files between local computers and remote clouds automatically. We also implemented the file encryption and decryption functionalities for users to encrypt and decrypt their files before uploading to clouds.