Stand between a radio transmitter and its receiver and you can intercept the signal. It is one of the most basic facts of wireless physics, and almost every wireless security system in the world is built around working with it. Researchers in Greece have found a way to work around it instead.
Researchers have now designed radio beams that do not travel in a straight line. The beams curve through space on their way from sender to receiver, and the signal is only strong enough to be intercepted at the intended destination. Anyone standing between the transmitter and the receiver picks up almost nothing.
The new paper, posted to the arXiv research server on 22 April 2026 by researchers at the University of Piraeus in Greece, studies what happens to wireless security when radio beams are shaped to follow a curved path instead of the usual straight one. The authors, Sotiris Droulias, Giorgos Stratidakis, and Angeliki Alexiou, show that these bending beams offer a fundamentally different kind of protection from eavesdropping, one that does not depend on encryption at all.
The approach works because of a shift happening in wireless communications that most people have not heard of. Next-generation networks like 6G are expected to use much larger antenna arrays than current mobile networks.
When an antenna array is large enough, the physics of how signals behave close to the antenna, in what engineers call the near field, becomes quite different from the physics that governs your current Wi-Fi or 4G signal. In the near field it becomes possible to shape radio waves in ways that would not work in conventional wireless systems. Curved, bending paths are one of those shapes.
The security advantage comes from the geometry. When a radio beam travels in a straight line, the signal is spread across the entire path between transmitter and receiver. An eavesdropper anywhere along that line picks up a portion of the signal. When the beam curves, the signal intensity along the straight-line path where an eavesdropper would logically sit is dramatically lower than at the intended receiver. The signal has taken a different route entirely.
The researchers tested this in two scenarios. The first is line-of-sight eavesdropping, where the attacker is positioned directly between the transmitter and receiver. The second is non-line-of-sight eavesdropping, where the attacker is positioned off to the side or at an unexpected angle. In both cases, the bending beam design outperformed conventional directed beams on secrecy rate, the standard measure of how much information can be sent securely.
This matters because most wireless security today is built on top of the signal rather than inside it. Encryption protects the content of what is transmitted, but the signal itself is still broadcast in a way that any receiver can pick up and try to decode.
Physical layer security aims to make interception physically impossible rather than just computationally difficult. If an eavesdropper cannot collect enough signal to work with in the first place, the content never needs to be protected by encryption alone.
The bending beam concept is not entirely new. The same research group published a paper in IEEE Transactions on Wireless Communications in 2025 showing how beams shaped to travel on curved paths could help 6G near-field networks communicate around obstacles and reach users on unusual trajectories. That paper focused on coverage. The new April 2026 paper is the first from this group to study what the curved beam design means specifically for security, and to quantify its advantage over standard beamforming in both line-of-sight and non-line-of-sight eavesdropping conditions.
Sources
Droulias, S., Stratidakis, G. and Alexiou, A. “Enhancing the Physical Layer Security with Bending Beams.” arXiv:2604.20583 [eess.SP]. Submitted 22 April 2026. https://arxiv.org/abs/2604.20583
Droulias, S., Stratidakis, G. and Alexiou, A. “Bending Beams for 6G Near-Field Communications.” IEEE Transactions on Wireless Communications, vol. 24, no. 2, pp. 1467–1480 (2025). https://dl.acm.org/doi/abs/10.1109/TWC.2024.3509548
The arXiv preprint version of this paper is also available at: https://arxiv.org/abs/2410.08099
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Ray Jackson holds a BSc in Electrical Engineering from the University of Manitoba and a PhD in Physics from Carleton University. His reporting interests include Current and Future Technologies, Engineering and Artificial Intelligence.