arXiv:1712.04981 · IEEE Transactions on Information Forensics and Security
An Improved Feedback Coding Scheme for the Wire-Tap Channel
Bin Dai, Yuan Luo
Abstract
The model of wiretap channel (WTC) is important as it constitutes the essence of physical layer security. Recently, it has been shown that a noiseless feedback channel from the legitimate receiver to the transmitter helps to increase the secrecy capacity of the WTC. However, the present feedback strategy focuses only on generating the key from the feedback signal and using this key to protect part of the transmitted message. This secret key-based feedback strategy has been proved to be optimal only for some degraded cases. In this paper, we propose a new feedback strategy for the WTC, where the feedback signal is not only used to generate the key but also used to generate cooperative information helping the legitimate parties to improve their encoding and decoding performance. We show that the proposed new strategy performs better than the already existing one, and the results are further explained via a binary example.