Google’s DNS-over-TLS is designed to make it harder for man-in-the-middle attackers to manipulate the DNS query or eavesdrop on your Internet connection. DNS queries are sent in clear text over UDP or TCP without encryption. Google says DNS queries and responses will be communicated over TLS-encrypted TCP connections. Google is not the first one to offer DNS-oversensitive DNS services, Cloudflare launched its new “1.1” last year, which claims to be the world’s fastest and privacy-focused secure DNS service.
Source: https://thehackernews.com/2019/01/google-dns-over-tls-security.html