Voices from the lab… Prabhat Raj Gautam, Research Fellow, Department of Computing, Imperial College London

Prabhat Raj Gautam is currently employed as a Research Fellow at the Department of Computing, Imperial College London. He earned a Master of Technology in Communications Engineering from the Indian Institute of Technology (IIT) Delhi and a PhD in Electronic and Electrical Engineering from the University of Leeds. His doctoral thesis was awarded the F.W. Carter Prize for the best thesis. His research areas include integrated sensing and communication (ISAC), reconfigurable intelligent surfaces (RIS), and hybrid precoding. His current work focuses on physical layer security, involving RIS and ISAC.

What specific challenge is your research trying to solve, and why does it matter now?

I am examining the security concerns posed by Reconfigurable Intelligent Surfaces (RISs) to communication and sensing in wireless networks. An RIS could eavesdrop on or disrupt communication and sensing, and I am investigating how RIS can interfere with sensing.

Future wireless communications operating at higher frequencies will utilise RIS to establish connections or extend coverage, making RISs widespread. Despite the clear benefits of RISs, we must acknowledge the security vulnerabilities they pose to wireless networks. It is crucial to study the security threats introduced by RISs so that we are well-informed and prepared to address these issues before their full adoption in future communication networks.

Can you walk us through a recent breakthrough or discovery and what it means for your field?

A recent paper titled “Sensing-Secure ISAC: Ambiguity Function Engineering for Impairing Unauthorized Sensing”explores how to secure sensing within an Integrated Sensing and Communication (ISAC) system.

The study addresses a key challenge: while ISAC signals support both communication and legitimate sensing (Alice), they can also be exploited by an eavesdropper (Eve) to passively extract target information. This creates a significant sensing-security risk.

To counter this, the paper proposes engineering artificial imperfections into the ambiguity function of the ISAC signal. These imperfections create ghost targets in Eve’s range profile, reducing her ability to detect and accurately estimate target information. Meanwhile, legitimate receivers are able to remove these artefacts through mismatched filtering, allowing authorised sensing and communication to continue unaffected.

What’s something the public might misunderstand about your area of research?

If we’re talking about the ‘general’ public, they would not understand terms like ISAC or even wireless communications. They might equate 6G with the internet. If we are talking about people like me, but those who work in other areas, they might think that sensing in ISAC (or just sensing in general), like communication, can be secured through encryption, which is clearly not the case.

How do you measure impact or success in your work?

The most obvious way to measure success is through publications, which I would describe as a tangible measure. Sometimes, your work may not directly lead to a publication, but it provides an in-depth understanding of the subject, which can shape or positively influence your future work. I would also consider this a form of success, though it is more intangible and perhaps less significant.