(April 6, 2020)
Asymmetric encryption is used during the “handshake”, which takes place prior to any data being sent. The handshake determines which cipher suite to use for the session – in other words, the symmetric encryption type – so that both browser and server agree. The TLS 1.2 protocol took multiple round trips between client and server, while TLS 1.3 is a much smoother process that requires only one trip. This latency saving shaves milliseconds off each connection.
Another characteristic of TLS 1.3 is that it can operate alongside DNS over HTTPS (DoH).