What Makes a VPN Tunnel Secure?
Surf the Internet without worries or minimise the risk of accessing distributed applications - thanks to VPN tunnels, you can surf the Internet safely.
Greater privacy and stronger security on public networks -- these are the biggest advantages of a VPN connection. It reliably connects distributed locations and even lets you securely access sensitive company data from an airport Wi-Fi. Modern work models like remote work or digital sales would be nearly impossible without this technology. On top of that, a VPN prevents third parties from analyzing your traffic data -- a significant benefit in today's privacy-conscious landscape. Sounds great, but how secure is a VPN tunnel really?
What Is a VPN Tunnel?
A Virtual Private Network (VPN) is a closed communication network built on publicly accessible infrastructure. While an open Wi-Fi network exposes you to a wide range of cybercrime threats, a VPN tunnel encrypts all communication and provides significantly greater security. Additionally, a VPN lets you mask or change your apparent location to access otherwise restricted information, data, and applications -- commonly known as bypassing "geoblocking."
How Does VPN Access Work?
VPN software encrypts all data exchanged between your computer and servers on the internet. Only the communication partners within this closed network can interact with each other. Neither your internet provider nor any third party can view the communication. The provider can only detect that data traffic is occurring -- the content and origin of the data remain encrypted and hidden. When a user connects to a network through a VPN tunnel, the network sees the computer as if it were located directly at the corporate office.
When using a VPN, you independently select an IP address. Unlike a standard IP address, this one is shared by all users on the service -- often several hundred at a time. This poses a major challenge for criminals: stealing account credentials becomes a Herculean task, since it is virtually impossible to identify a single individual among the multitude of users sharing the same IP address. More information about VPN tunnels.
How to Identify a Secure VPN Tunnel
Organizations with the capacity and -- more importantly -- the expertise should consider setting up their own VPN server. Since future developments such as company growth or technological advances are often hard to predict, it is wise to think big but start small and scale as needed. If running your own server is not feasible, commercial software solutions are readily available. For individuals, this is typically the only practical option. However, you should scrutinize any offering carefully, because not everything that promises security actually delivers it. So what makes a good VPN solution? For a VPN tunnel to be truly secure, you need to verify the authenticity (= unambiguous identification of authorized users), confidentiality, and integrity (= data cannot be altered) of the connection.
Reliable providers give their users access to established security protocols, making browsing significantly safer. However, Point-to-Point Tunneling Protocol (PPTP) should be treated with caution -- it is now considered outdated and insecure. Modern alternatives include L2TP, IPsec, IKEv2 (Internet Key Exchange Version 2), and OpenVPN. OpenVPN in particular is one of the most widely used options, available in both paid and free versions. It encrypts with up to 256-bit encryption, the highest level currently available, keeping users anonymous online. Reliable VPN solutions also include a kill switch that temporarily disconnects you from the internet to prevent data leaks if the connection drops. Some VPNs additionally block potentially harmful websites and pop-ups before they can cause damage.
Network security is still frequently overestimated, while the threat of cybercrime is too often underestimated. A VPN provides a straightforward security measure that complements any security strategy. The days when a VPN connection noticeably degraded performance are long gone, and with the broad range of products available, there is a solution for every use case. That said, you should be aware that a VPN tunnel does not guarantee complete security -- absolute protection remains unattainable. However, by using a VPN, both organizations and individuals are on significantly safer ground. NIST has published a comprehensive guide on the topic of VPN.