XHTTP

VPN Encryption Alone Cannot Hide Traffic from Network Detection Systems

A Habr user known as mr_tom detailed why encrypted VPN connections remain detectable despite their encryption. Observers can identify connections through visible metadata such as server IP addresses, ports, transport protocols, handshake patterns, packet sizes, timing intervals, and overall flow behavior. Simple DPI systems block traffic by restricting known IPs or ports, while advanced filters build traffic fingerprints and use active probing to verify suspicious endpoints. The popular combination of VLESS, XHTTP, and REALITY operates across different layers rather than functioning as three equivalent VPN protocols. Even traffic on port 443 can be distinguished from standard HTTPS by analyzing handshake details and subsequent packet behavior. The core conclusion is that no universally unblockable VPN exists, as detection can rely on IP blocking, new signatures, or active verification regardless of encryption strength.