Information-theoretic Physical Layer Security for Satellite Channels

TL;DR

This paper reviews the application of information-theoretic physical layer security, specifically wiretap coding, to satellite channels, exploring its potential for keyless, unconditionally secure communication.

Contribution

It introduces a general construction of wiretap coding tailored for satellite channels and discusses its applicability and system design implications.

Findings

Wiretap coding can be applied to satellite channels for enhanced security.

Keyless physical layer security is feasible under certain satellite channel conditions.

System design must consider specific satellite channel characteristics for optimal security.

Abstract

Shannon introduced the classic model of a cryptosystem in 1949, where Eve has access to an identical copy of the cyphertext that Alice sends to Bob. Shannon defined perfect secrecy to be the case when the mutual information between the plaintext and the cyphertext is zero. Perfect secrecy is motivated by error-free transmission and requires that Bob and Alice share a secret key. Wyner in 1975 and later I.~Csisz\'ar and J.~K\"orner in 1978 modified the Shannon model assuming that the channels are noisy and proved that secrecy can be achieved without sharing a secret key. This model is called wiretap channel model and secrecy capacity is known when Eve's channel is noisier than Bob's channel. In this paper we review the concept of wiretap coding from the satellite channel viewpoint. We also review subsequently introduced stronger secrecy levels which can be numerically quantified and are keyless unconditionally secure under certain assumptions. We introduce the general construction of wiretap coding and analyse its applicability for a typical satellite channel. From our analysis we discuss the potential of keyless information theoretic physical layer security for satellite channels based on wiretap coding. We also identify system design implications for enabling simultaneous operation with additional information theoretic security protocols.