A new cryptographic chip allows checking the authenticity of products. With this, the chip helps counter counterfeit products. It is small enough to fit on almost any product.
Counterfeit products cause a $2 trillion loss to companies worldwide on an annual basis, according to 2018 figures from Organization for Economic Co-operation and Development. However, tackling counterfeit goods is not easy. For instance, fraudsters use complex supply routes to make the origin and thus the authenticity of products more difficult to verify. In practice, this leads to companies receiving counterfeit products and components without being aware of it.
Current tags have their limitations
Wireless tags have been available for some time to check the authenticity of products. However, they have their limitations. One example are RID tags, which in practice are too large to place on small products such as medical or industrial components, automotive parts or chips. In addition, RFID tags are not secure.
While other alternative tags are secure against cloning and hacking, they tend to be larger and also consume a relatively large amount of energy. To still make the chips smaller, concessions have to be made. For instance, this requires scrapping antennas that enable wireless communication. Or using chips that are not capable of strong encryption.
Readable from relatively far away
A new chip removes these limitations. It is a chip only a few millimetres in size. It consumes so little energy that it can be powered with energy generated by photovoltaic diodes. The chip does not have a battery.
The chip is capable of transmitting data over a distance of 5 centimetres, which is a relatively large distance for such chips. To do this, the chip uses an energy-free technique that operates at a frequency hundreds of times higher than that of RFID chip.
The special chip is not fitted with an enclosure, as it is relatively large and also increases production costs. To enable the use of an integrated antenna and wireless communication over longer distances, it was chosen to communicate via a high terahertz frequency, which lies between microwaves and infrared rays.
Encryption
Regarding encryption, the researchers point out that RFID protocols usually communicate unencrypted. At the same time, they can be read using readily available scanners, without using authentication. Thus, with the right reader, anyone can read an RFID tag.
The new chip therefore uses 'elliptic curve cryptography'. This technique combines a private key owned only by a user with a public key, which is publicly known. Only if the recipient has the combination of these two keys is the chip readable.
In time, researchers hope to further increase the range so that tags can be scanned at a greater distance. The greater range will make it possible to set up a central hub in a logistics centre, for example, that automatically scans all tags. "We think we can turn a reader into a central hub that doesn't need to be close to the tag. All these chips can send their signal to talk to this one reader," explains graduate student Mohamed I. Ibrahim. Security is key here.
Tag of everything
The researchers call their inventions the 'tag of everything'. Ruonan Han, professor of electrical and computer engineering and head of the Terahertz Integrated Electronics Group at Microsystems Technology Laboratories (MTL), says: "If I want to track something in the logistics of, say, a single bolt, a dental implant or a chip, current RFID tags are unable to do so. We have built a cheap and small chip with no housing, batteries or other external components that stores and transmits sensitive data."
Han was involved in the project alongside final-year students Mohamed I. Ibrahim, Muhammad Ibrahim Wasiq Khan and Chiraag S. Juvekar. Also involved were former postdocs Wanyeong Jung and Rabia Tugce Yazicigil; and Anantha P. Chandrakasan, Dean of the MIT School of Engineering and Professor of Electrical Engineering and Computer Science.
Author: Wouter Hoeffnagel
