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).