Rethinking the Role of Network Stacks for Website Fingerprinting Defenses

While encryption has become ubiquitous across the Internet, there is growing concern that website fingerprinting and other traffic analysis attacks could undermine the confidentiality guarantees encryption is meant to provide. Over the past decade, these attacks have become increasingly effective, highlighting the urgent need to deploy traffic obfuscation countermeasures. Although defenses have already been proposed in the literature, they remain inefficient partly because they are implemented at the application-level, which limits their control over packet sequences. This paper advocates for integrating packet sequence obfuscation support directly into host network stacks, where the fine-grained packet operations that defenses require can be effectively enforced.