ScrambleSuit: A Polymorph Network Protocol to Circumvent Censorship
This addresses the problem of circumventing censorship for users in restricted regions, offering a novel method to enhance privacy and access.
The paper tackles the problem of Internet censorship using deep packet inspection by proposing ScrambleSuit, a polymorph network protocol that obfuscates application data to defend against active probing and fingerprinting, with results showing little overhead and effective lightweight obfuscation.
Deep packet inspection technology became a cornerstone of Internet censorship by facilitating cheap and effective filtering of what censors consider undesired information. Moreover, filtering is not limited to simple pattern matching but makes use of sophisticated techniques such as active probing and protocol classification to block access to popular circumvention tools such as Tor. In this paper, we propose ScrambleSuit; a thin protocol layer above TCP whose purpose is to obfuscate the transported application data. By using morphing techniques and a secret exchanged out-of-band, we show that ScrambleSuit can defend against active probing and other fingerprinting techniques such as protocol classification and regular expressions. We finally demonstrate that our prototype exhibits little overhead and enables effective and lightweight obfuscation for application layer protocols.