Connections use TLS

Immediately after the initial packet setting up a connection, the initiatorsends a crypto frame that starts setting up the secure layer handshake. Thesecurity layer uses TLS 1.3 security.

There is no way to opt-out or avoid using TLS for a QUIC connection. Theprotocol is designed to be hard for middle-boxes to tamper with, in orderto help prevent ossification of the protocol.