You can use DropBox and CryptSync (only for Windows) to securely transfer large files. Both applications are free, with DropBox (see Wikipedia) being a popular cloud storage application and CryptSync an application to encrypt your confidential data before they are uploaded.
DropBox is now a relatively safe means of transferring large files (2 GB free storage) to your clients because DropBox does encrypt your data during the transfer and on its servers. However, because the encryption is done by DropBox the keys are stored on their servers as well. This means, that if they get hacked your data might get into the wrong hands. Therefore we came up with this solution of combining DropBox with CryptSync.
How it works
You first sign up for DropBox and install the application. This is needed to sync the data you place into the folder created by the DropBox installer to the cloud. All the files placed directly into the DropBox folder will be synced to the cloud.
In the second step, you create a source folder at a location of your choice for all the files that need to be extra safe (imagine legal files you would like to share with a client) and will get some extra encryption.
The third step is to install CryptSync. You provide CryptSync with the source folder, which you created in step 2, and with the target folder, which is the DropBox folder. You also need to provide a password that will be used to encrypt your files. One more choice to make is whether you want to sync manually or if you want CryptSync to run in the background and encrypt and sync automatically what you place into the CryptSync folder.
Once the files are on DropBox you can create a download link that you can send to your client. And don’t forget to send the CryptSync password to the client as well but in a separate email for additional security.
One more thing. You also probably don’t want your files being infected with a virus before you even upload them to Dropbox. To make sure this doesn’t happen you should always have a good virus scanner installed on your computer.
DropBox available for: Windows, Mac OSX, Linux
CryptSync available for: Windows 7 or later
