Camoufler: Accessing The Censored Web By Utilizing Instant Messaging Channels

Piyush Kumar Sharma, Devashish Gosain, Sambuddho Chakravarty

Abstract: Free and open communication over the Internet is considered a fundamental human right, essential to prevent repressions from silencing voices of dissent. This has led to the development of various anti-censorship systems. Recent systems have relied on a common blocking resistance strategy i.e., incurring collateral damage to the censoring regimes, if they attempt to restrict such systems. However, despite being promising, systems built on such strategies pose additional challenges, viz., deployment limitations, poor QoS etc. These challenges prevent their wide scale adoption. Thus, we propose a new anti-censorship system, Camoufler, that overcomes aforementioned challenges, while still maintaining similar blocking resistance. Camoufler leverages Instant Messaging (IM) platforms to tunnel client's censored content. This content (encapsulated inside IM traffic) is transported to the Camoufler server (hosted in a free country), which proxies it to the censored website. However, the eavesdropping censor would still observe regular IM traffic being exchanged between the IM peers. Thus, utilizing IM channels as-is for transporting traffic provides unobservability, while also ensuring good QoS, due to its inherent properties such as low-latency message transports. Moreover, it does not pose new deployment challenges. Performance evaluation of Camoufler, implemented on five popular IM apps indicate that it provides sufficient QoS for web browsing. E.g., the median time to render the homepages of Alexa top-1k sites was recorded to be about 3.6s, when using Camoufler implemented over Signal IM application.