To safely transfer data via an unsecured Internet connection, companies make use of Virtual Private Network (VPN) solutions. A VPN represents the coming together of two separate networks to form a self-contained logical network. This technology enables subsidiaries to be connected to the company headquarters, or employees to set up a home office. But it also gives members of staff who work out in the field the opportunity to establish a secure connection with the company in order to exchange data.

A VPN is a purely software-based solution: no special network hardware is required to create one. To use a public network such as the Internet to establish a VPN connection between the computer at a home office and the company network, for example, the VPN client software replicates the configuration of the company network virtually on the home office computer. The client software connects via the Internet to the VPN dial-in node, and after successful authentication, enables communication between the devices using a secured VPN protocol such as IPsec, TLS/SSL or PPTP. The home office workstation thus becomes a component of the private company network. A secure connection established between the VPN dial-in node and the remote device via a public network, such as the Internet, is referred to as a VPN tunnel.

Simple diagram of a VPN tunnel

A VPN tunnel is not just used to connect individual computers to a network (site-to-end) but can, for example, be used to connect the local networks of several subsidiaries together (site-to-site). It is also possible to use VPN to establish a secure connection to a server without having access to the entire company network (end-to-end).

The VPN client software Hamachi works using similar principles, and has already been discussed in this article. Connections initiated via Hamachi are not established directly between clients right from the start - they are first conducted via a so-called mediation server that is responsible for authenticating the client. This fact, coupled with the fact that the Hamachi source text cannot be viewed publicly, may pose a security risk when transferring sensitive data.

Users who have a laptop as well as a desktop computer and wish to be able to access the data on their home PC from elsewhere, and who do not wish to use Hamachi for the reasons named above, can quickly and easily establish an end-to-end VPN connection using Windows Vista and the standard tools it provides. The prerequisite for convenient operation and rapid data transfer is a suitably fast Internet connection: ideally, you want at least a fast DSL connection with an appropriate upstream speed.