Physical Layer Security for Semantic Communications

With a paradigm shift from classic full message communication, the goal of semantic communications is to transmit the semantic information (e.g., the necessary information to perform a specific task). The goal of this project is to study the semantic communications in wireless network in the presence of passive attackers, who are interested in eavesdropping the information. For this purpose, we focus on the physical layer security approaches that use the inherent randomness of the wireless channels to generate wiretap codes with the ability of hiding the secure data from the eavesdroppers. The first step is to build a basic framework for this setup, using information-theoretical concepts with both reliability and secrecy metrics. Next, the fundamental limits of the proposed performance metrics in the basic model are characterized by providing achievability and converse proofs. Finally, the results of the basic model are extended to the wireless channels using communication theoretic approaches. This enables us to analyse the performance of these systems with a stochastic approach.

Department/School

School of Computer Science and Electrical Engineering

Project Description

In the classic communication setup, the goal is to transmit an almost perfect version of the message. However, the goal of semantic communications is to transmit the semantic information, for example the necessary information to perform a specific task at the receiver. This changes the basic mathematical models (such as the Shannon’s point-to-point channel setup), which are used to analyse the performance of the communication systems. In particular, it is needed to develop semantic-aware models and approaches for the communication systems with security constraints. Here, we study the passive eavesdropping attackers, who observe the transmitted signals due to the openness of wireless channels. One of the main concerns is to define a suitable metric to measure the security leakage to the attackers. When the goal of message transmission is to perform a task, considering the zero information leakage might be stringent. The next step is to design appropriate strategies to guarantee the secrecy constraint based on this metric. In this project, we focus on the physical layer security approaches that use the inherent randomness of the wireless channels to generate wiretap codes with the ability of hiding the secure data from the eavesdroppers. Using the model and the strategy, the goal is to derive the lower and upper bounds on the capacity of this model and to extend the basic model to the wireless networks, considering their effects such as fading, randomly located users, etc. This enables us to analyse the performance of these systems with a stochastic approach. The steps (methodology) of the project are as:

1. Building a basic framework for the semantic communication in presence of eavesdroppers, using information-theoretical concepts. This includes the network model as well as the performance metrics (both reliability and secrecy metrics).
2. Characterizing the fundamental limits of the proposed performance metrics in the basic model, by providing achievability and converse proofs.
3. Extending the results of the basic model to the wireless channels using communication theoretic approaches.

Candidate Profile

A candidate with the knowledge of information theory and communication theory is preferred.

How to Apply

Applications should be submitted via the Information and Communication Systems PhD programme page. In place of a research proposal you should upload a document stating the title of the projects (up to 2) that you wish to apply for and the name(s) of the relevant supervisor. You must upload your full CV and any transcripts of previous academic qualifications. You should enter ’Faculty Funded Competition’ under funding type.

Funding

The studentship will provide a stipend at UKRI rates (currently £17,668 for 2022/23) and tuition fees for 3.5 years. An additional bursary of £1700 per annum for the duration of the studentship will be offered to exceptional candidates.