Previous messages provide the key to achieve shannon capacity in a wiretap channel

Abstract

We consider a wiretap channel and use previously transmitted messages to generate a secret key which increases the secrecy capacity. This can be bootstrapped to increase the secrecy capacity to the Shannon capacity without using any feedback or extra channel while retaining the strong secrecy of the wiretap channel.

Enhancing secrecy rates in a wiretap channel

“…We also note that the following proof is valid for N 1 > 1. The proof for N 1 = 1 is different from the proposed proof and one can refer to [23] for details of the proof. We will denote the codeword X k = (X k,1 , X k,2 )…”

Enhancing Secrecy Rate Region for Recent Messages for a Slotted Multiple Access Wiretap Channel to Shannon Capacity Region

“…In this section we extend the coding-decoding scheme of [22] for a point-to-point channel to enhance the achievable secrecy rates for a MAC-WT. We recall that in [22] the system is slotted with a slot consisting of n channel uses. The first message is transmitted by using the wiretap code of [1] in slot 1.…”

“…Shah et al in [22] propose a simple coding scheme, without any feedback channel or access to some key, and enhance the secrecy capacity of a wiretap channel to the Shannon capacity of the main channel. In this work also, only the message currently being transmitted is secure w.r.t.…”

“…all the information of Eve. In this paper we extend the coding/decoding schemes of [22] and [23] to a multiple access wiretap channel and prove that we can achieve Shannon capacity region of the MAC as the secrecy-rate region while keeping all recent messages secure w.r.t. the information possessed by Eve till present.…”

“…In Section 1 we define the channel model and recall some previous results which will be used in this paper. We extend our coding/decoding scheme of [22] to two user discrete memoryless MAC-WT (DM-MAC-WT) in Section 2 and prove the achievability of Shannon capacity region, under the security constraint that only the currently transmitted message is secured w.r.t. all the data received by Eve.…”