IPSEC VPN connection is usually only available to multiple offices of the same company. In this case, we cannot offer VPN to customers. (we can only offer it to our employees or big enterprise customers).
You don't need VPN for high security. You can use SSL. DriveHQ.com website supports SSL / HTTPS; our FTP server also supports FTP over SSL.
If you use a Windows PC, you can install DriveHQ FileManager, which supports both HTTPS/SSL and Encrypted Folder. If you use Encrypted Folder feature, it is extremely secure as you can encrypt your files locally before they are uploaded. The encryption key is never sent to DriveHQ server.