Study Exposes Security Vulnerabilities in Terahertz Data Links
October 16, 2018 | Brown UniversityEstimated reading time: 3 minutes
A new study shows that terahertz data links, which may play a role in ultra-high-speed wireless data networks of the future, aren’t as immune to eavesdropping as many researchers have assumed. The research, published in the journal Nature, shows that it is possible for a clever eavesdropper to intercept a signal from a terahertz transmitter without the intrusion being detected at the receiver.
“The conventional wisdom in the terahertz community has been that it’s virtually impossible to spy on a terahertz data link without the attack being noticed,” said Daniel Mittleman, a professor in Brown University’s School of Engineering and a coauthor of the research. “But we show that undetected eavesdropping in the terahertz realm is easier than most people had assumed and that we need to be thinking about security issues as we think about designing network architectures.”
Because of its higher frequency, terahertz radiation can carry up to 100 times more data than the microwaves used in wireless communication today, which makes terahertz an attractive option for use in future wireless networks. Along with enhanced bandwidth, it has also been generally assumed that the way in which high-frequency waves propagate would naturally enhance security. Unlike microwaves, which propagate in wide-angle broadcasts, terahertz waves travel in narrow, very directional beams.
“In microwave communications, an eavesdropper can put an antenna just about anywhere in the broadcast cone and pick up the signal without interfering with the intended receiver,” Mittleman said. “Assuming that the attacker can decode that signal, they can then eavesdrop without being detected. But in terahertz networks, the narrow beams would mean that an eavesdropper would have to place the antenna between the transmitter and receiver. The thought was that there would be no way to do that without blocking some or all of the signal, which would make an eavesdropping attempt easily detectable by the intended receiver.”
Mittleman and colleagues from Brown, Rice University and the University at Buffalo set out to test that notion. They set up a direct line-of-site terahertz data link between a transmitter and receiver, and experimented with devices capable of intercepting signal. They were able show several strategies that could steal signal without being detected — even when the data-carrying beam is very directional, with a cone angle of less than 2 degrees (in contrast to microwave transmission, where the angle is often as large as 120 degrees).
One set of strategies involves placing objects at the very edge of a beam that is capable of scattering a tiny portion of the beam. In order for a data link to be reliable, the diameter of the beam must be slightly larger than the aperture of the receiver. That leaves a sliver of signal for an attacker to work with without casting a detectable shadow on the receiver.
The researchers showed that a flat piece of metal could redirect a portion of the beam to a secondary receiver operated by an attacker. The researchers were able to acquire a usable signal at the second receiver with no significant loss of power at the primary receiver.
The team showed an even more flexible approach (from the attacker’s perspective) by using a metal cylinder in the beam instead of a flat plate.
“Cylinders have the advantage that they scatter light in all directions, giving an attacker more options in setting up a receiver,” said Josep Jornet, an assistant professor of electrical engineering at Buffalo and a study co-author. “And given the physics of terahertz wave propagation, even a very small cylinder can significantly scatter the signal without blocking the line-of-sight path.”
The researchers went on to demonstrate another type of attack involving a lossless beam splitter that would also be difficult, if not impossible, to detect. The beam splitter placed in front of a transmitter would enable an attacker to steal just enough to be useful, yet not so much that it would set off alarm bells among network administrators.
The bottom line, the researchers say, is that while there are inherent security enhancements associated with terahertz links in comparison with lower frequencies, these security improvements are still far from foolproof.
“Securing wireless transmission from eavesdroppers has been a challenge since the days of Marconi,” said Edward Knightly, professor of electrical and computer engineering at Rice University and a study coauthor. “While terahertz bands take a huge leap in this direction, we unfortunately found that a determined adversary can still be effective in intercepting the signal.”
Suggested Items
Koh Young Showcases Award-winning Inspection Solutions at SMTconnect with SmartRep in Hall 4A.225
04/25/2024 | Koh Young TechnologyKoh Young Technology, the industry leader in True 3D measurement-based inspection solutions, will showcase an array of award-winning inspection and measurement solutions at SMTconnect alongside its sales partner, SmartRep, in booth 4A.225 at NürnbergMesse from June 11-13, 2023. The following offers a glimpse into what Koh Young will present at the tradeshow:
Book Excerpt: The Printed Circuit Assembler’s Guide to... Factory Analytics
04/24/2024 | I-Connect007 Editorial TeamIn our fast-changing, deeply competitive, and margin-tight industry, factory analytics can be the key to unlocking untapped improvements to guarantee a thriving business. On top of that, electronics manufacturers are facing a tremendous burden to do more with less. If you don't already have a copy of this book, what follows is an excerpt from the introduction chapter of 'The Printed Circuit Assembler’s Guide to... Factory Analytics: Unlocking Efficiency Through Data Insights' to whet your appetite.
Real Time with... IPC APEX EXPO 2024: Industrial Quality Solutions from Zeiss
04/23/2024 | Real Time with...IPC APEX EXPOEditor Nolan Johnson and Herminso Gomez of Zeiss Group discuss the company's industrial quality solutions, with a focus on X-ray technology. Zeiss provides a range of microscopy options and Herminso highlights the advantages of X-ray technology for aerospace, medical, and consumer electronics sectors.
Altair Acquires Cambridge Semantics, Powering Next-Generation Enterprise Data Fabrics and Generative AI
04/22/2024 | AltairAltair a global leader in computational intelligence, acquired Cambridge Semantics, a modern data fabric provider and creator of one of the industry’s leading analytical graph databases.
I-Connect007 Editor’s Choice: Five Must-Reads for the Week
04/19/2024 | Marcy LaRont, PCB007 MagazineFor my must-read picks of the week, I’m highlighting Parker Capers, a young professional seeking employment, solid counsel from Dan Beaulieu on what your post-show plan should look like, more information and insight on “chiplets” and the need for secure data transfer standards from columnist Preeya Kuray, as well as Matt Stevenson’s design for reality wisdom. It’s a reminder to download one of our newest books (there are several) you don't want to miss if you are an assembler.