Speaker: Richard Yang

Title: Randomness and Privacy in Communications


Security and privacy are fundamental concerns in today’s world. Recent revelations have shown that traditional cryptographic techniques do not provide the security that was expected. Moreover there are situations where even the presence of communications needs to be hidden and remain private; cryptographic techniques cannot provide such privacy. This has called into question how security and privacy can be provided. In this talk we investigate how randomness in the environment can be used to provide privacy in wireless communications. We consider the canonical problem where Alice wants to communicate with Bob in the presence of an adversary, Willie the Warden without Willie ever realizing that the communication is taking place. We consider a variety of wireless and wireline communication systems and determine how much information Alice can send privately to Bob without being detected. For example in wireless and optical communication systems, we establish that Alice can send  bits (and no more) to Bob in time . On the other hand in a wireline channel where Alice can manipulate packet timings in order to encode information, Alice can convey much more information. Last, we report experimental results that corroborate these results.