Methods of Enhancing TLS Encrypted ClientHello Traffic Privacy

In recent years, the development of network security protocols has focused on enhancing user privacy. A key innovation is the Transport Layer Security Encrypted ClientHello (TLS ECH) amendment. It hides vulnerable service parameters that are currently transmitted in plain text and reveals the requested service. However, traffic metadata, such as packet lengths and inter-arrival times, remain a source of privacy leaks. Existing methods for addressing these vulnerabilities typically do not modify the connection establishment process but rather focus on modifying application-level traffic. However, traffic patterns during connection establishment still reveal the service to which the client is connecting. Therefore, this study develops a new method of TLS ECH connection metadata obfuscation to enhance user privacy. The proposed solution reduces the effectiveness of modern classifiers hRFTC, hC4.5, and UW from 97–99 to 15–31% in the F‑score metric. At the same time, the connection establishment time increases at most two-fold.