Social media websites are blocked in many regimes where Internet censorship is applied. In this paper, we introduce Mailet, an unobservable transport proxy which enables the users to access social websites by email applications. Without assuming the Mailet servers are trustworthy, Mailet can support the services requiring privileges without having the complete credential. Particularly, the credential is split and distributed in two Mailet servers, and neither of them can recover the credential alone. To recover the credential in a TLS record message, we propose a highly efficient Galois/ Counter Mode(GCM) based secure computation, which can enable the two servers to conceal their separate credential copies in the computation. We implemented a prototype for Twitter.com to demonstrate the usability and security of Mailet.
 Google approves an app that steals all your data, http://www.technologyreview.com/.
 Openssl, https://www.openssl.org/.
 L. V. Ahn, M. Blum, N. J. Hopper, and J. Langford. Captcha: Using hard ai problems for security. In Proceedings of the 22Nd International Conference on Theory and Applications of Cryptographic Techniques, 2003.
 Y. Aumann and Y. Lindell. Security against covert adversaries: Efficient protocols for realistic adversaries. In Theory of Cryptography, pages 137-156. Springer, 2007.
 C. Brubaker, A. Houmansadr, and V. Shmatikov. Cloudtransport: Using cloud storage for censorship-resistant networking. In Proceedings of PETS’14, 2014.
 J. Callas, L. Donnerhacke, H. Finney, D. Shaw, and R. Thayer. Openpgp message format. RFC 4880, 2007.
 T. Dierks. The transport layer security (tls) protocol version 1.2. 2008.
 R. Dingledine, N. Mathewson, and P. Syverson. Tor: The second-generation onion router. In Proceedings of USENIX Security’04, 2004.
 Z. Durumeric, D. Adrian, A. Mirian, J. Kasten, E. Bursztein, N. Lidzborski, K. Thomas, V. Eranti, M. Bailey, and J. A. Halderman. Neither snow nor rain nor mitm...: An empirical analysis of email delivery security. In Proceedings of IMC’15, 2015.
 C. Evans, C. Palmer, and R. Sleevi. Public key pinning extension for http. RFC 7469, 2015.
 J. Geddes, M. Schuchard, and N. Hopper. Cover your acks: Pitfalls of covert channel censorship circumvention. In Proceedings of CCS’13, 2013.
 A. Houmansadr, C. Brubaker, and V. Shmatikov. The parrot is dead: Observing unobservable network communications. In Proceedings of IEEE Symposium on Security and Privacy’13, 2013.
 A. Houmansadr, G. T. Nguyen, M. Caesar, and N. Borisov. Cirripede: Circumvention infrastructure using router redirection with plausible deniability. In Proceedings of CCS’11, 2011.
 A. Houmansadr, T. Riedl, N. Borisov, and A. Singer. I Want my Voice to be Heard: IP over Voice-over-IP for Unobservable Censorship Circumvention. In Proceedings of NDSS’13, 2013.
 A. Houmansadr, E. L. Wong, and V. Shmatikov. No direction home: The true cost of routing around decoys. In Proceedings of NDSS’14, 2014.
 Y. Huang, D. Evans, J. Katz, and L. Malka. Faster secure two-party computation using garbled circuits. In Proceedings of USENIX Security’11, 2011.
 J. Karlin, D. Ellard, A. W. Jackson, C. E. Jones, G. Lauer, D. P. Mankins, and W. T. Strayer. Decoy routing: Toward unblockable internet communication. In Proceedings of FOCI’11, 2011.
 H. Kwak, C. Lee, H. Park, and S. Moon. What is twitter, a social network or a news media? In Proceedings of WWW’10, 2010.
 S. Li, M. Schliep, and N. Hopper. Facet: Streaming over videoconferencing for censorship circumvention. In Proceedings of WPES’14, 2014.
 D. Malkhi, N. Nisan, B. Pinkas, Y. Sella, et al. Fairplaysecure two-party computation system. In Proceedings of USENIX Security’04, 2004.
 H. M. Moghaddam, B. Li, M. Derakhshani, and I. Goldberg. Skypemorph: Protocol obfuscation for Tor bridges. In Proceedings of CCS’12, 2012.
 M. Schuchard, J. Geddes, C. Thompson, and N. Hopper. Routing around decoys. In Proceedings of CCS’12, 2012.
 Z. Tufekci. Networked politics from tahrir to taksim: Is there a social media-fueled protest style? In Digital Media and Learning Central. http://dmlcentral.net/blog/zeyneptufekci/networked-politics-tahrir-taksim-there-social-media-fueled-protest-style, June 2013.
 S. Vieweg, A. L. Hughes, K. Starbird, and L. Palen. Microblogging during two natural hazards events: What twitter may contribute to situational awareness. In Proceedings of CHI’10, 2010.
 Q. Wang, X. Gong, G. T. K. Nguyen, A. Houmansadr, and N. Borisov. Censorspoofer: Asymmetric communication using IP spoofing for censorship-resistant web browsing. In Proceedings of CCS’12, 2012.
 B. Warf. Global geographies of the Internet, volume 1. Springer Science & Business Media, 2012.
 Z. Weinberg, J. Wang, V. Yegneswaran, L. Briesemeister, S. Cheung, F. Wang, and D. Boneh. StegoTorus: A camouflage proxy for the Tor anonymity system. In Proceedings of CCS’12, 2012.
 E. Wustrow, C. M. Swanson, and J. A. Halderman. Tapdance: End-to-middle anticensorship without flow blocking. In Proceedings of USENIX Security’14), 2014.
 E. Wustrow, S. Wolchok, I. Goldberg, and J. A. Halderman. Telex: Anticensorship in the network infrastructure. In Proceedings of USENIX Security’11, 2011.
 A. C. Yao. Protocols for secure computations. In 2013 IEEE 54th Annual Symposium on Foundations of Computer Science, pages 160-164. IEEE, 1982.
 W. Zhou, A. Houmansadr, M. Caesar, and N. Borisov. Sweet: Serving the web by exploiting email tunnels. In Proceedings of HotPETs’13, 2013.