ProtonVPN is a virtual private network service produced by the company that runs the ProtonMail high-security email service. ProtonVPN is similarly designed to be a high-security VPN suitable for journalists and political activists. The service exclusively uses ciphers designed for Perfect Forward Secrecy, which means that a compromised encryption key cannot be used to decrypt past sessions. ProtonVPN's parent company is based in Switzerland, a country with famously strict privacy laws. Switzerland is not a member of either the five eyes or the fourteen eyes global surveillance networks. ProtonVPN also includes a kill switch feature that will disable internet service entirely when the VPN connection unexpectedly drops. Many other VPN systems react to a connection drop as if it were a deliberate shutdown of the VPN and begin sending traffic over the regular internet. ProtonVPN's free tier allows access from a single device from up to 3 countries. Paid plans offer more devices and higher speeds. Client software is available for Windows, macOS, and Linux computers as well as Android and iOS mobile devices.