An official website of the United States government
Transcending the capabilities of traditional architectures, metasurfaces offer nearlimitless control over the fundamental electromagnetic properties of wireless signals, presenting new opportunities for wireless communication. However, they also bring forth unprecedented security challenges, particularly for millimeter-wave and sub-THz wireless backhaul links employed for many critical functions, such as financial trading on Wall Street. In this article, we expose a new category of aerial ''MetaSurface-in-the-Middle'' attacks, wherein an adversary armed with an on-drone metasurface, MetaFly, can intercept wireless backhaul links with an almost imperceptible trace. Strikingly, such adversarial metasurfaces can be fabricated in minutes using standard office items like a foil sheet and a laminator. The attack is implemented and experimentally evaluated in both a large indoor atrium and outdoor rooftops in a large metropolitan area, demonstrating the adversary's ability to establish a secondary diffraction beam for eavesdropping while maintaining minimal impact on legitimate communication.
more »
« less
This content will become publicly available on January 1, 2027
Metasurface-in-the-Middle Attack: EM Wavefront Manipulation Threats and Countermeasures
Metasurfaces enable controllable manipulation of electromagnetic waves and have been shown to be valuable for wireless communications in many diverse ways. In this paper, we explore the notion that these useful components could also provide opportunities for a malicious agent. In particular, we define and experimentally demonstrate for the first time a “MetaSurface-in-the-Middle” (MSITM) attack. In this attack, the adversary Eve places a metasurface in the path of a directive transmission between Alice and Bob and targets to re-direct a portion of the signal towards herself, without being detected. Specifically, we show how Eve can design a metasurface that induces abrupt phase changes at the interface of the metasurface to controllably diffract directional links and establish furtive eavesdropping links. We explore the theoretical foundations of the MSITMattack and demonstrate that an effective metasurface can be prototyped in under 5 min at a minimal cost. We experimentally demonstrate the attack in a THz time-domain system and perform a set of over-the-air experiments. Our results indicate that the MSITM attack yields an acute vulnerability that can significantly reduce empirical secrecy capacity while leaving a minimal energy footprint, making the attack challenging to detect.
more »
« less
- PAR ID:
- 10696497
- Publisher / Repository:
- IEEE
- Date Published:
- Journal Name:
- IEEE Transactions on Networking
- Volume:
- 34
- ISSN:
- 2998-4157
- Page Range / eLocation ID:
- 1674 to 1688
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
We consider the multiple-input multiple-output (MIMO) wiretap channel with intersymbol interference (ISI) in which a transmitter (Alice) wishes to securely communicate with a receiver (Bob) in presence of an eavesdropper (Eve). We focus on the practically relevant setting in which there is no channel state information (CSI) at Alice about either of the channels to Bob or Eve, except statistical information about the ISI channels (i.e., Alice only knows the effective number of ISI taps). The key contribution of this work is to show that even with no CSI at Alice, positive secure degrees of freedom (SDoF) are achievable by carefully exploiting a) the heterogeneity of the ISI links to Bob and Eve, and b) the relative number of antennas at all the three terminals. To this end, we propose a novel achievable scheme that carefully mixes information and artificial noise symbols in order to exploit ISI heterogeneity to achieve positive SDoF. To the best of our knowledge, this is the first work to explore the idea of exploiting ISI channel length heterogeneity to achieve positive SDoF for the MIMO wiretap channel with no CSI at the legitimate transmitter.more » « less
-
Considerable recent research interest has focused on the possibility of using metasurfaces for manipulation of terahertz wavefronts. For example, metasurfaces allow a beam to be targeted in any desired direction using strategically placed meta-elements. With rapid prototyping techniques, metasurfaces can be fabricated quickly and at a low cost. These techniques also permit the fabrication of metasurfaces on flexible substrates which can be bent easily. This opens the possibility of employing such devices as conformable arrays on non-flat surfaces. To explore this idea, we experimentally and numerically analyze the performance of a terahertz metasurface printed on paper, as a function of its radius of curvature. We observe that when the metasurface is bent, the direction of the refracted beam is minimally impacted and the performance of the metasurface remains very similar to when it is flat. This conclusion will simplify the design and modeling criteria for conformable metasurfaces.more » « less
-
Reconfigurable intelligent surface (RIS) technology can enhance the performance of wireless systems, but an ad-versary can use such technology to deteriorate communication links. This paper explores an RIS-based attack on multi-user wireless systems that require channel reciprocity for time-division duplexing (TDD). We demonstrate that deploying an RIS with a non-diagonal phase shift matrix can compromise channel reciprocity and lead to poor TDD performance. The attack can be achieved without transmission of signal energy, without channel state information (CSI), and without synchronization with the legitimate system, and thus it is difficult to detect and counteract. We provide an extensive set of simulation studies on the impact of such an attack on the achievable sum rate of the legitimate system, and we design a heuristic algorithm for optimizing the attack in cases where some partial knowledge of the CSI is available. Our results demonstrate that this channel reciprocity attack can significantly degrade the performance of the legitimate system.more » « less
-
Interactive web-based applications play an important role for both service providers and consumers. However, web applications tend to be complex, produce high-volume data, and are often ripe for attack. Attack analysis and remediation are complicated by adversary obfuscation and the difficulty in assembling and analyzing logs. In this work, we explore the web application analysis task through log file fusion, distillation, and visualization. Our approach consists of visualizing the logs of web and database traffic with detailed function execution traces. We establish causal links between events and their associated behaviors. We evaluate the effectiveness of this process using data volume reduction statistics, user interaction models, and usage scenarios. Across a set of scenarios, we find that our techniques can filter at least 97.5% of log data and reduce analysis time by 93-96%.more » « less
