IISc develops record-breaking device to improve data encryption, make digital data safer

BENGALURU: Bengaluru-based Indian Institute of Science (IISc) has developed a record-breaking true random number generator (TRNG) which can improve data encryption and provide improved security for sensitive digital data such as credit card details, passwords and other personal information.

The study describing this device has been published in the journal ACS Nano.  

Encrypted information can be decoded only by authorised users who have access to a cryptographic “key”. But the key needs to be unpredictable and, therefore, randomly generated to resist hacking.

Cryptographic keys are typically generated in computers using pseudorandom number generators (PRNGs), which rely on mathematical formulae or pre-programmed tables to produce numbers that appear random but are not.

In contrast, a TRNG extracts random numbers from inherently random physical processes, making it more secure.

An IISc release said that in the breakthrough TRNG device, random numbers are generated using the random motion of electrons. It consists of an artificial electron trap constructed by stacking atomically-thin layers of materials like black phosphorus and graphene. The current measured from the device increases when an electron is trapped, and decreases when it is released. Since electrons move in and out of the trap in a random manner, the measured current also changes randomly. The timing of this change determines the generated random number.

“You cannot predict exactly at what time the electron is going to enter the trap. So, there is an inherent randomness that is embedded in this process,” said Kausik Majumdar, Associate Professor at Department of Electrical Communication Engineering (ECE) which has developed the device. Majumdar led the team which developed the device.

Nithin Abraham, a PhD student at the Department of ECE, who is part of the team, said “Almost everything we do on the internet is encrypted for security. The strength of this encryption depends on the quality of random number generation.”

The team’s electronic TRNG is also more compact than its clunkier counterparts that are based on optical phenomena, said Abraham. “Since our device is purely electronic, millions of such devices can be created on a single chip,” said Majumdar.

He and his group plan to improve the device by making it faster and developing a new fabrication process that would enable the mass production of these chips.

Majumdar said the performance of the device on the standard tests for cryptographic applications designed by the US National Institute of Standards and Technology (NIST) has exceeded his own expectations. “When the idea first struck me, I knew it would be a good random number generator, but I didn’t expect it to have a record-high min-entropy,” he added.