New York, Feb 18 (IANS): Engineers at the Massachusetts Institute of Technology (MIT) in the US have developed an ID tag that can reveal with almost accuracy whether an item is real or fake, the institute said on Sunday.

The researchers improved a security vulnerability in an earlier cryptographic ID tag to develop an anti-tampering ID tag that still offers the benefits of being tiny, cheap and secure, the MIT said in a statement.

The earlier tag had a security vulnerability with traditional RFIDs.

The researchers produced a light-powered anti-tampering tag that is about 4 square millimetres in size.

They also demonstrated a machine-learning model that helps detect tampering by identifying similar glue pattern fingerprints with more than 99 per cent accuracy, said MIT.

The earlier ID tag used terahertz waves, which are smaller and travel much faster than radio waves.

Using terahertz waves with a 1-millimetre wavelength allowed the researchers to make a chip that does not need a larger, off-chip antenna, said the team.

After passing through the tag and striking the object’s surface, terahertz waves are reflected, or backscattered, to a receiver for authentication.

“How those waves are backscattered depends on the distribution of metal particles that reflect them,” the authors n oted.

The researchers put multiple slots onto the chip so waves can strike different points on the object’s surface, capturing more information on the random distribution of particles.

“These responses are impossible to duplicate, as long as the glue interface is destroyed by a counterfeiter,” said Ruonan Han, an associate professor in EECS, who leads the Terahertz Integrated Electronics Group in the Research Laboratory of Electronics.

The authentication system is limited by the fact that terahertz waves suffer from high levels of loss during transmission, so the sensor can only be about 4 centimetres from the tag to get an accurate reading.

The MIT team plans to address these limitations in future work.