http://o54hon2e2vj6c7m3aqqu6uyece65by3vgoxxhlqlsvkmacw6a7m7kiad.onion/en/blog/2018/10/17/signals-trustworthy-vpns
Secure systems are required for privacy, and since Mullvad’s beginning, security has always been deeply ingrained in our culture. In our app we offer such security features as a kill switch, DNS leak protection, and IPv6 support, all of which we were either first or among the first. We only utilize the two best VPN protocols, OpenVPN and WireGuard (we were an early adopter of the former and we pioneered the latter).