eprintid: 10199016
rev_number: 7
eprint_status: archive
userid: 699
dir: disk0/10/19/90/16
datestamp: 2024-10-29 10:02:44
lastmod: 2024-10-29 10:02:44
status_changed: 2024-10-29 10:02:44
type: article
metadata_visibility: show
sword_depositor: 699
creators_name: Xu, Hao
creators_name: Wong, Kai-Kit
creators_name: Caire, Giuseppe
title: A New Achievable Region of the K-User MAC Wiretap Channel with Confidential and Open Messages Under Strong Secrecy
ispublished: inpress
divisions: UCL
divisions: B04
divisions: F46
keywords: Discrete memoryless (DM) multiple access wiretap (MAC-WT) channel; 
strong secrecy; secret and open messages; 
achievable rate region
note: This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions.
abstract: This paper investigates the achievable region of a K -user discrete memoryless (DM) multiple access wiretap (MAC-WT) channel, where each user transmits both secret and open (i.e., non-confidential) messages. All these messages are intended for the legitimate receiver (Bob), while the eavesdropper (Eve) is only interested in the secret messages. In the achievable coding strategy, the confidential information is protected by open messages and also by the introduction of auxiliary messages. When introducing an auxiliary message, one has to ensure that, on one hand, its rate is large enough for protecting the secret message from Eve and, on the other hand, the resulting sum rate (together with the secret and open message rate) does not exceed Bob’s decoding capability. This yields an inequality structure involving the rates of all users’ secret, open, and auxiliary messages. To obtain the rate region, the auxiliary message rates must be eliminated from the system of inequalities. A direct application of the Fourier-Motzkin elimination procedure is elusive since a) it requires that the number of users K is explicitly given, and b) even for small K = 3, 4, …, the number of inequalities becomes extremely large. We prove the result for general K through the combined use of Fourier-Motzkin elimination procedure and mathematical induction. This paper adopts the strong secrecy metric, characterized by information leakage . To prove the achievability under this criterion, we analyze the resolvability region of a K -user DM-MAC channel (not necessarily a wiretap channel). In addition, we show that users with zero secrecy rate can play different roles and use different strategies in encoding their messages. These strategies yield non-redundant (i.e., not mutually dominating) rate inequalities. By considering all possible coding strategies, we provide a new achievable region for the considered channel, and show that it strictly improves those already known in the existing literature by considering a specific example.
date: 2024-10-01
date_type: published
publisher: Institute of Electrical and Electronics Engineers (IEEE)
official_url: http://dx.doi.org/10.1109/tit.2024.3471662
oa_status: green
full_text_type: other
language: eng
primo: open
primo_central: open_green
verified: verified_manual
elements_id: 2327850
doi: 10.1109/TIT.2024.3471662
lyricists_name: Xu, Hao
lyricists_name: Wong, Kai-Kit
lyricists_id: HXUCX90
lyricists_id: KWONG98
actors_name: Wong, Kai-Kit
actors_id: KWONG98
actors_role: owner
full_text_status: public
publication: IEEE Transactions on Information Theory
issn: 0018-9448
citation:        Xu, Hao;    Wong, Kai-Kit;    Caire, Giuseppe;      (2024)    A New Achievable Region of the K-User MAC Wiretap Channel with Confidential and Open Messages Under Strong Secrecy.                   IEEE Transactions on Information Theory        10.1109/TIT.2024.3471662 <https://doi.org/10.1109/TIT.2024.3471662>.    (In press).    Green open access   
 
document_url: https://discovery.ucl.ac.uk/id/eprint/10199016/1/MAC_wiretap.pdf