Secure Communication over Adversarial Channel
Digital Communications play an important role in modern worlds, and it is crucial to consider the security problems associated with network communication. This dissertation explores the use of physical layer characteristics of communication channels and network multipath to build secure and reliable communication in adversarial setting. We investigate four ad- versarial models: limited view adversary channel, adversarial wiretap channel, adversarial wiretap channel with public discussion, and Secure Message Transmission. The first three models are about secure communication using physical layer characters, and the last is about using network multipath for communication. We first consider secure and reliable communication over a wiretap channel with an active adversary. We consider on adversarial channel model, in which the adversary is able to eavesdrop the communication between the sender and the receiver, and also corrupt the communication by adding adversarial noise. The model of limited view adversary focuses on reliable communication over this channel, and the construction of limited view adversary code achieves reliable communication in this setting. Adversarial wiretap channel studies secure and reliable transmission over this adversarial channel. We obtain an upper bound on the capacity of this channel, and construct an adversarial wiretap code that provides secure and reliable communication over this channel. By allowing communicants to have access to a public discussion channel, secure communication becomes possible over adversarial wiretap channel for a wider range of parameters. We then consider on Secure Message Transmission in networks. We propose a new construction for secure message transmission protocols using a list decodable code and a message authentication code. Our protocol has optimal transmission rate and provides the highest reliability among all known comparable protocols.