A team at the Department of Electrical Communication Engineering (ECE), Indian Institute of Science (IISc) has developed a true random number generator (TRNG), which, the team says, 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 the TRNG device has been published in the journal ACS Nano.
“Almost everything we do on the internet is encrypted for security. The strength of this encryption depends on the quality of random number generation,” explained Nithin Abraham, a PhD student who is a part of a team led by Kausik Majumdar, Associate Professor at ECE, which has developed the TRNG device.
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, 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, the IISc release explained.
In IISc’s 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 TRNG 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,” it added.
“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,” explained Prof. Majumdar.
The performance of the TRNG device on the standard tests for cryptographic applications designed by the US National Institute of Standards and Technology (NIST) has exceeded their expectations. “Min-entropy is a parameter used to measure the performance of TRNGs. Its value ranges from 0 [completely predictable] to 1 [completely random]. The TRNG device from Majumdar’s lab showed a record-high min-entropy of 0.98, a significant improvement over previously reported values, which were around 0.89,” the release said, adding that the team’s electronic TRNG is also more compact than its clunkier counterparts that are based on optical phenomena.
