CacheBrowser: Bypassing Chinese Censorship without Proxies Using Cached Content

The cached Internet content served by content delivery networks (CDN) comprises a large fraction of today’s Internet traffic, yet, there is little study on how real-world censors deal with blocking forbidden CDN-hosted Internet content. We investigate the techniques used by the Great Firewall of China to block CDN-hosted content, and demonstrate that blocking CDN content poses unique technical and non-technical challenges to the censors. We therefore design a client-side circumvention system, CacheBrowser, that leverages the censors’ difficulties in blocking CDN content. We implement CacheBrowser and use it to unblock CDN-hosted content in China with a download latency significantly smaller than traditional proxy-based circumvention systems like Tor. CacheBrowser’s superior quality-ofservice is thanks to its publisher-centric approach, which retrieves blocked content directly from content publishers with no use of third-party proxies. Categories and Subject Descriptors C.2.0 [C...

• Type: Journal
• Year: 2015
• Where: CCS
• Authors: John Holowczak, Amir Houmansadr
• Keywords: CCS 2015, Security Privacy