QUIC

QUIC (Quick UDP Internet Connections) is a general-purpose transport protocol developed by Google and standardised by the IETF. It runs over UDP instead of TCP and integrates TLS 1.3 encryption into the transport layer itself, eliminating the separate TLS handshake overhead. QUIC connections survive network changes (IP address changes) because connections are identified by a connection ID rather than the source IP:port tuple. HTTP/3 is built entirely on QUIC. For proxy infrastructure, QUIC poses challenges: many firewalls block UDP, requiring fallback to TCP/TLS. QUIC is also an emerging fingerprinting surface for bot detection.