Abhinav Narain (Georgia Institute of Technology) will present his defense talk "Near-Field Deniable Communication" on Wednesday, May 24, 2017 in the CITP conference room, 3rd Fl, Sherrerd Hall at 11am (Webcast : http://bit.ly/2qFJXx6) Title: Near-Field Deniable Communication ----- Abhinav Narain School of Computer Science College of Computing Georgia Institute of Technology Committee --------- Prof. Nick Feamster (Adviser, School of Computer Science, Princeton University) Prof. Mostafa Ammar, (School of Computer Science, Georgia Institute of Technology) Prof. Taesoo Kim, (School of Computer Science, Georgia Institute of Technology) Prof. Alex Snoeren, (Dept. of Computer Science, University of California, San Diego) Date: Wednesday, May 24, 2017 Time: 11 am to 1 pm EST Location: CITP conference room, third floor, Sherrerd Hall, Princeton University Webcast : http://bit.ly/2qFJXx6 There is constant surveillance by employers, corporations, and governments. Long people have wanted to keep their communication private but With increasing interest of state and private organizations and corporations in the daily lives of people, such a discussion is on the rise. This dissertation develops techniques and systems that empower users to evade such intentions of adversaries. Our work builds from the observation to leverage randomness in physical nature of the world everywhere, specifically using technologies such as wireless and power-lines networks in urban settings. This thesis is divided into two parts. First part, we develop Denali, which allows deniable communication in wireless 802.11 networks. Denali achieves this by leveraging the weakness of wireless networks which has packet corruption due to its ubiquitous nature of being broadcast medium. This is the first such system which uses off-the-shelf commodity hardware to users. In the second part, we explore a different network primarily used for powering devices in building infrastructure -- power-line network. We build Power-line Whisperer, a physical layer covert communication channel. Power-line Whisperer is the first of its kind of system to make it easier for people to to do deniable communication on power-line networks. Both these systems allow the users to do point-to-point communication and defend against powerful adversaries who might be interested in snooping on the message exchange for malicious reasons.