Amazon S3 is the online storage service offered by Amazon Web Services (AWS). Its interface (S3 REST API) is public and has become the de-facto standard for cloud storage. To be able to use Amazon S3 service, you first need to sign up for an AWS account. The account is free and you will pay only for the amount of storage and traffic that you actually use.

For more information click on the following link :  http://aws.amazon.com/s3/faqs/

DragonDisk is a file manager that allows clients to copy, move, delete, synchronize... files between a client’s local drive and the cloud (such as Amazon S3, Google Cloud Storage, and other S3 compatible storage).

DragonDisk is a "freeware" (Free as in beer). It is distributed free of charge for any private and corporate use. It is provided "as is" without warranty of any kind. You may download it and install it on as many machines as you wish, copy it for other people; but you may not incorporate DragonDisk into any "commercial" product or service.

DragonDisk is not a backup software but is a "file manager". If you want to backup your data, you should use a backup solution.

Google provides two different storage services: Google Cloud Storage, and Google Drive.

DragonDisk is compatible with Google Cloud Storage but not with Google Drive. Google Drive does not offer an S3 compatible API, and Google Cloud Storage is not currently integrated with Google Docs.

DragonDisk is still in development and there is no documentation available yet. But if you're familiar with the Amazon S3 AWS Console, you will have no troubles using DragonDisk. A Quick Start Guide is available to help you get started.

For installing the package from a terminal, perform the following steps :

 
Ubuntu 11.10 and later require an old version of libssl to be installed :

http://packages.ubuntu.com/trusty/amd64/libssl0.9.8/download

Ubuntu 32-bit :

Download the native package and install like this :
wget http://download.dragondisk.com/dragondisk_1.0.5-0ubuntu_i386.deb
sudo apt-get install libqt4-dbus libqt4-network libqt4-xml libqtcore4 libqtgui4
sudo dpkg -i dragondisk_1.0.5-0ubuntu_i386.deb

Ubuntu  64-bit :

Download the native package and install like this :
wget http://download.dragondisk.com/dragondisk_1.0.5-0ubuntu_amd64.deb
sudo apt-get install libqt4-dbus libqt4-network libqt4-xml libqtcore4 libqtgui4
sudo dpkg -i dragondisk_1.0.5-0ubuntu_amd64.deb

To start the Application, enter :
dragondisk

You can also start it from the KDE/Gnome GUI menu  ( Applications -> Internet -> DragonDisk )

This feature is not available in DragonDisk.

DragonDisk uses the OpenSSL library and produces the same result as OpenSSL.
The encryption is directly equivalent to these commands :

# encrypt / decrypt using 256-bit AES in CBC mode
openssl enc -md sha1 -salt -aes-256-cbc -in clearfile -out cryptedfile -pass pass:myPassword
openssl enc -md sha1 -d -aes-256-cbc -in cryptedfile -out clearfile -pass pass:myPassword

# encrypt / decrypt using Blowfish in CBC mode
openssl enc -md sha1 -salt -bf-cbc -in clearfile -out cryptedfile -pass pass:myPassword
openssl enc -md sha1 -d -bf-cbc -in cryptedfile -out clearfile -pass pass:myPassword

# encrypt /decrypt using three key triple DES EDE in CBC mode
openssl enc -md sha1 -salt -des-ede3-cbc -in clearfile -out cryptedfile -pass pass:myPassword
openssl enc -md sha1 -d -des-ede3-cbc -in cryptedfile -out clearfile -pass pass:myPassword