To combat supply chain counterfeiting, which can cost companies billions of dollars annually, MIT researchers have invented a cryptographic ID tag that is small enough to fit on virtually any product and verify its authenticity. Rob Matheson from MIT News reports
MIT researchers’ millimetre-sized ID chip integrates a cryptographic processor, an antenna array that transmits data in the high terahertz range, and photovoltaic diodes for power. Image: courtesy of the researchers, edited by MIT News
Counterfeiters tend to use complex routes that include many checkpoints, making it challenging to verify their origins and authenticity. Consequently, companies can end up with imitation parts. Wireless ID tags are becoming increasingly popular for authenticating assets as they change hands at each checkpoint. But these tags come with various size, cost, energy, and security trade-offs that limit their potential.
Popular radio-frequency identification (RFID) tags, for instance, are too large to fit on tiny objects such as medical and industrial components, automotive parts, or silicon chips. They don’t contain any tough security measures. Some tags are built with encryption schemes to protect against cloning and ward off hackers, but they’re large and power hungry. Shrinking the tags means giving up both the antenna package — which enables radio-frequency communication — and the ability to run strong encryption.
Researchers have developed a millimetre-sized chip which runs on relatively low levels of power supplied by photovoltaic diodes. It also transmits data at far ranges, using a power-free ‘backscatter’ technique that operates at a frequency hundreds of times higher than RFIDs.
“We call it the ‘tag of everything.’ And everything should mean everything,” says researcher Ruonan Han, an associate professor in the Department of Electrical Engineering and Computer Science and head of the Terahertz Integrated Electronics Group in the Microsystems Technology Laboratories (MTL). “If I want to track the logistics of, say, a single bolt or tooth implant or silicon chip, current RFID tags don’t enable that. We built a low-cost, tiny chip without packaging, batteries, or other external components which stores and transmits sensitive data.”
Tiny holes in the chip’s antennae allow light from the reader to pass through to photodiodes underneath that convert the light into about 1 volt of electricity. In the researchers’ system, the tag uses a private key and a reader’s public key to identify itself only to valid readers. That means any eavesdropper who doesn’t possess the reader’s private key should not be able to identify which tag is part of the protocol by monitoring just the wireless link.
Even though it’s the size of a sesame seed, the ID tag (zoomed in, right) can send wireless communications at greater reader distances than much larger RFID tags (left) and can run cryptographic algorithms to help secure nearly any product in the supply chain. Image: courtesy of the researchers
Pushing the limits
Currently, the signal range sits around 5cm, which is considered a far-field range — and allows for convenient use of a portable tag scanner. Next, the researchers hope to “push the limits” of the range even further. Eventually, they’d like many of the tags to ping one reader positioned somewhere far away in, say, a receiving room at a supply chain checkpoint. Many assets could then be verified rapidly.
The chips are so small, easy to make, and inexpensive that they can also be embedded into larger silicon computer chips, which are especially popular targets for counterfeiting.
“The US semiconductor industry suffered $7 billion to $10 billion in losses annually because of counterfeit chips,” researcher Wasiq Khan says. “Our chip can be seamlessly integrated into other electronic chips for security purposes, so it could have huge impact on industry. Our chips cost a few cents each, but the technology is priceless,” he quipped.
This article is reproduced with the permission of MIT News. Images reused under a Creative Commons Attribution Non-Commercial No Derivatives license.
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