Coset Codes in a Multi-hop Network

Error-correction coding techniques have been used to exploit imperfections in the physical layer of the communications protocol stack to obtain both reliability and security without the need for secret keys. In a multi-hop network, however, colluding eavesdropping nodes can share information to effectively reduce errors in the eavesdropping channels and, hence, overcome the secrecy offered through coding. This paper presents a simple method for preventing an eavesdropper from gaining an advantage by listening to several transmissions of the same codeword. The technique can be used in multi-hop networks, and communications systems that employ automatic repeat request (ARQ) for data reliability.