TLS 1.3

The transport security used in QUIC is using TLS 1.3 (RFC8446) and there are never any unencryptedQUIC connections.

TLS 1.3 has several advantages compared to older TLS versions but a primaryreason for using it in QUIC is that 1.3 changed the handshake to require fewerroundtrips. It reduces protocol latency.

The Google legacy version of QUIC used a custom crypto.