Website Fingerprinting on Early QUIC Traffic

Cryptographic protocols have been widely used to protect the user's privacy and avoid exposing private information. QUIC (Quick UDP Internet Connections), as an alternative to traditional HTTP, demonstrates its unique transmission characteristics: based on UDP for encrypted resource transmission, accelerating web page rendering. However, existing encrypted transmission schemes based on TCP are vulnerable to website fingerprinting (WFP) attacks, allowing adversaries to infer the users' visited websites by eavesdropping on the transmission channel. Whether QUIC protocol can effectively resisting to such attacks is worth investigating. In this work, we demonstrated the extreme vulnerability of QUIC under WFP attacks by comparing attack results under well-designed conditions. We also study the transferability of features, which enable the adversary to use proven effective features on a special protocol attacking a new protocol. This study shows that QUIC is more vulnerable to WFP attacks than HTTPS in the early traffic scenario but is similar in the normal scenario. The maximum attack accuracy on QUIC is 56.8 % and 73 % higher than on HTTPS utilizing Simple features and Transfer features. The insecurity characteristic of QUIC explains the dramatic gap. We also find that features are transferable between protocols, and the feature importance is partially inherited on normal traffic due to the relatively fixed browser rendering sequence and the similar request-response model of protocols. However, the transferability is inefficient when on early traffic, as QUIC and HTTPS show significantly different vulnerability when considering early traffic. We also show that attack accuracy on QUIC could reach 95.4 % with only 40 packets and just using simple features, whereas only 60.7 % when on HTTPS.