How secure is VPN?

Virtual Private Networks (VPNs) provide secure communication mechanisms, such as encryption and tunneling, enabling users to circumvent censorship, to access geo-blocked services, or to securely access an organization’s resources remotely. However, VPN services come with different vulnerabilities or security issues, including weak security protocols, privacy issues, and reliability. First, this project aims at detecting different VPN servers worldwide, then, at measuring how vulnerable these detected VPN service are to different kinds of attacks such as version downgrade attack.

In this project, we perform Internet-wide active measurements to find and characterize the VPN server deplyoment. To realize this, we plan to send VPN requests using different VPN protocols such as L2TP/IPsec, SSTP, OpenVPN, IKEv2, Cisco AnyConnect, PPTP, Wireguard, etc. to the Internet hosts. In this way, we find responsive IP addresses.

Then, targeting responsive IP addresses, we perform a full handshake to measure different aspects of a VPN service, such as performance and vulnerabilities. Detecting VPN servers might also help in detecting VPN traffic which is an open research question sometimes addressed by machine learning techniques.