Secret message transmission by HARQ with multiple encoding

Abstract

Abstract-Secure transmission between two agents, Alice and Bob, over block fading channels can be achieved similarly to conventional hybrid automatic repeat request (HARQ) by letting Alice transmit multiple blocks, each containing an encoded version of the secret message, until Bob informs Alice about successful decoding by a public error-free return channel. In existing literature each block is a differently punctured version of a single codeword generated with a Wyner code that uses a common randomness for all blocks. In this paper instead we propose a more general approach where multiple codewords are generated from independent randomnesses. The class of channels for which decodability and secrecy is ensured is characterized, with derivations for the existence of secret codes. We show in particular that the classes are not a trivial subset (or superset) of those of existing schemes, thus highlighting the novelty of the proposed solution. The result is further confirmed by deriving the average achievable secrecy throughput, thus taking into account both decoding and secrecy outage.

Achievable secrecy rates over MIMOME Gaussian channels with GMM signals in low-noise regime

“…We focus our analysis on the low-noise regime, i.e., in the limit σ 2 → 0, and we consider the achievable secrecy rates that are obtained by imposing U = c in (6). We assume that the number of antennas at Bob are sufficient to guarantee perfect discrimination among signals coming from the different Gaussian classes in the low-noise regime.…”

“…Seminal works from the '70s have established the secrecy capacity of a wiretap channel where agent Alice aims at transmitting a secret message to agent Bob while not revealing any information to an eavesdropper agent Eve [1], [2]. Since then, a number of other scenarios have been investigated, including the broadcast channel with confidential messages (BCC) case where multiple receivers require a common message and possibly a different secret message each [3], the case of secret message transmission over parallel channels [4], [5], fading channels [6] and the multiple-input multiple-output multiple-eavesdropper (MIMOME) case [7]- [9]. In this paper we focus on the MIMOME channel which may find many important applications in wireless communication systems where the transmitter and the receivers are equipped with multiple antennas.…”

MIMOME Gaussian Channels with GMM Signals in High-SNR Regime: Fundamental Limits and Tradeoffs

“…Their focus was centered first on the analysis of discrete memoryless and Gaussian channels [12,22]. Since then, a number of different scenarios have been investigated, including the broadcast channel with confidential messages (BCC) case where multiple receivers require a common message and possibly a different secret message each [3], the case of secret message transmission over parallel channels [1,13], fading channels [20] and the multipleinput multiple-output multiple-eavesdropper (MIMOME) case [10, 15,19], even particularized to OFDM transmission [18]. In this chapter we focus on the MIMOME channel which finds many important applications in wireless communication systems where the transmitter and the receivers are equipped with multiple antennas.…”