Researchers have developed a way to peek inside electronic parts as they're running and plan to see if they can snoop encrypted data
Terahertz waves have been an exciting area of research in the past few years because they can be used to examine the internal structures of objects without the risks associated with X-rays. Now one research team has used the tiny waves to peer into the inner workings of transistors while they're operating, and is exploring whether the technique could be used to read any data stored in a chip.
As reported by IEEE Spectrum (via Tom's Hardware), the multinational research group (comprising engineers from universities in Australia, Germany, and the USA) studied the behaviour of 'packaged semiconductor devices' in the low/sub-terahertz part of the electromagnetic spectrum. This is roughly in the boundary where microwaves and infrared waves overlap, in terms of wavelength.
However, as terahertz waves are far larger than the transistors found inside processors used in an average gaming PC, the group targeted the sort of electronic components you see soldered on a circuit board, such as a 1N4007 diode and a BC548B transistor.
Using a technique called homodyne detection, the research group was able to observe expected behaviours of these components during use, something that "typical terahertz detection schemes would not be able to see," according to Daniel Mittleman, professor of engineering at Brown University.
Research lead Withawat Withayachumnankul, professor of engineering at Adelaide University, explained to IEEE Spectrum that the work, once developed further and refined, could be useful for checking the operation of electronic components that need to stay working, e.g. in power delivery systems, where you don't want to shut things down.
The report also notes that the professor is "aiming to use the technique to read encrypted data in chips, which could have implications for security." However, before your alarm bells go a-clanging, it's worth noting that terahertz waves can only penetrate non-metallic materials, so any processor or chip covered by a heatspreader/heatsink is pretty much safe.
And even for those devices that are only covered by a plastic or organic package, the multi-layer nature of today's chips, typically stuffed with lots of copper interconnects, poses a natural barrier to terahertz investigation. But if there's one thing researchers love, it's a challenge that seems impossible to get around, and I wouldn't be surprised if the next time I'm writing about terahertz waves, engineers have come up with a totally novel solution.