In brief

Researchers have made use of the inherent randomness in a resistive random-access memory device to generate true random numbers for cybersecurity.

© A*STAR Institute of Materials Research and Engineering (IMRE)

An ultrathin shield defends against cyberattacks

11 Dec 2020

Instead of software, hardware that can generate true random numbers could be the key to ensuring cybersecurity.

It’s all online: from shopping and banking to work meetings and social networking, the internet is an indispensable part of our daily lives. Being connected, however, can be a risky business. Our devices are vulnerable to cyberattacks—increasingly sophisticated attempts by hackers to maliciously disable computers or steal data.

One way to protect sensitive data is to use encryption, a process of scrambling the information using random numbers that are known only to the sender and receiver of the message. Currently, these random numbers are approximated by software, which could be hacked. “True random numbers are preferred but also more challenging to achieve as they should follow certain statistical rules to ensure the integrity of the randomness,” explained Dongzhi Chi, a Principal Scientist at A*STAR’s Institute of Materials Research and Engineering (IMRE).

Instead of software, Chi and his team turned to hardware to generate true random numbers, exploiting the intrinsic randomness in the physical properties of a resistive random-access memory (ReRAM) device.

Although ReRAMs have been proposed as true random number generators in the past, they tend to degrade over time, ultimately leaving weak spots in the computer’s cybersecurity armor. To improve the stability of their ReRAM device, the researchers used repeated ultrathin layers of a semiconductor called MoS2, sandwiching them between insulating polymers. “This structure allowed us to keep the thickness of the active layer to a few nanometers without sacrificing the electrical properties,” added study co-corresponding author Henry Medina, a Research Scientist at IMRE.

The new and improved ReRAMs were put to the test in a single cell which displayed ten random states—five times more than the typical binary random states. “Normally, random numbers are generated in a binary way, providing ‘1’ or ‘0’ states,” Chi explained. “Our method of generating multiple random states within a single cell helps to reduce the amount of hardware used.”

Now that they have applied for a patent on their invention, the team is looking to transition this technology to an industrial setting. Tackling the efficient production scale-up and reducing mechanical damage during manufacturing are among their primary concerns.

“After achieving these goals, we should be in a good position to engage industry partners for possible technology transfer, licensing or a potential start-up,” said Chi.

The A*STAR-affiliated researchers contributing to this research are from the Institute of Materials Research and Engineering (IMRE).

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Chai, J., Tong, S., Li, C., Manzano, C., Li, B., et al., MoS2/Polymer Heterostructures Enabling Stable Resistive Switching and Multistate Randomness. Advanced Materials, 2002704 (2020) | article

About the Researchers

Dongzhi Chi received his BSc from Jilin University, China, in 1984 and MSc from Shanghai Institute of Ceramics, Chinese Academy of Science, in 1987. From 1987 to 1992, he worked at Shanghai Institute of Ceramics on amorphous semiconductor thin films and their applications to photovoltaic devices and laser printers. He was also a visiting scholar at the James Franck Institute, University of Chicago, from 1990 to 1991. After obtaining his PhD from Pennsylvania State University in 1998, Chi joined A*STAR’s Institute of Materials Research and Engineering (IMRE), where he is currently a Principal Scientist and program manager of the Science and Engineering Research Council Pharos 2D semiconductor materials program.
Henry Medina received his PhD from National Tsing Hua University, Taiwan, in 2012. He has postdoctoral and industrial work experience and large area synthesis and manipulation of 2D materials. He joined A*STAR’s Institute of Materials Research and Engineering (IMRE) in 2016 as a Research Scientist. His research interests focus on the development of 2D technologies for commercialization.

This article was made for A*STAR Research by Wildtype Media Group