Approaching Communication Unobservability Through Randomized Routing and Unpredictable Aging

Abstract

Providing anonymous communication on networks of interconnected computers is an active area of research which aims to enhance the privacy of the users of such networks. Communication unobservability is a stronger property compared to anonymity that attempts to guarantee that the adversaries will not even notice that a communication between a sender and a receiver is happening. In networks where an active global adversary may be present, it is assumed that at all times, all nodes in the network are potentially being monitored and also that at any time, any node should be treated as a possible adversary. This thesis work introduces a set of requirements which, if followed in any system, provides enhanced anonymous communication. Furthermore, following these requirements, a new anonymous networking system was designed. This system provides communication unobservability in the presence of active global adversaries through randomized routing and unpredictable aging. Randomized routing is used to obfuscate the message routing pattern and the communication path, and unpredictable aging is used to prevent indefinite postponement of messages when routing randomly.