Build‐in wiretap channel I with feedback and LDPC codes by soft decision decoding
Gaoyuan Zhang, Hong Wen, Jiexin Pu, Jie Tang · IET Communications · 2017
Many approaches to build a wiretap channel (WTC) by multi‐input multi‐output system have been introduced. Different from those approaches, the authors propose a feedback method combined with the low‐density parity‐check (LDPC) codes for building the WTC I (WTC‐I) to achieve unconditional security under single‐input single‐output system by the soft decision decoding. The novel approach establishes the WTC‐I on both the binary symmetric channel and binary input additive white Gaussian noise channel. In order to keep the eavesdropper be fully ignorant about the secret information, randomness is added to the feedback signals from the destination by taking advantage of feedback. In addition, the message to be sent is encoded by the LDPC codes such that it can be correctly decoded by a legitimate receiver. Furthermore, the secret information transmission capacity can be improved by the soft decision decoding.