PeLEDs offer to make encryption cheaper and more sustainable

Role of QRNGs

To encrypt information, a random number generator is used, which can either be a computer program or the hardware itself. Various random number generators offer varying degrees of unpredictability and security. According to the researchers, hardware is a much safer choice since physical processes are in charge of regulating randomness. The hardware technique that produces the finest randomness is QRNGs, which are based on quantum processes.

“In cryptography, it’s not only important that the numbers are random, but that you’re the only one who knows about them. With QRNGs, we can certify that a large amount of the generated bits is private and thus completely secure. And if the laws of quantum physics are true, it should be impossible to eavesdrop without the recipient finding out," said Guilherme B Xavier, a researcher at the Department of Electrical Engineering at Linköping University, in a statement. 

The team has now shown that PeLEDs can be successfully employed to implement modern and highly secure quantum random number generation protocols instead of lasers that are typically used to generate the random numbers in the encryption process.

Affordable and environmentally friendly

The properties of perovskite used, which is based on an indium tin oxide (ITO)-coated glass substrate, make it a cheaper and more environmentally friendly alternative in QRNGs. The material's optical and mechanical qualities are important drivers for utilization, and also has a smaller carbon footprint over its full life cycle.

“It’s possible to use, for example, a traditional laser for QRNG, but it’s expensive. If the technology is eventually to find its way into consumer electronics, it’s important that the cost is kept down and that the production is as environmentally friendly as possible. In addition, PeLEDs don’t require as much energy to run,” said Feng Gao, a professor at the University's Department of Physics, Chemistry, and Biology, in a statement. 

The researchers claim that their model has passed the stringent NIST randomness test suite and has "guaranteed the privacy of at least 71% of the generated random numbers by implementing our QRNG with the MDI approach," said the study.

The next phase is to refine the substance further to eliminate lead from the perovskite and increase its lifespan, which is now 22 days. The team hopes that within five years, their new QRNG might be used in cybersecurity. 

The details of their study have been published in the journal Nature. 

Abstract:

The recent development of perovskite light-emitting diodes (PeLEDs) has the potential to revolutionize the fields of optical communication and lighting devices, due to their simplicity of fabrication and outstanding optical properties. Here we demonstrate that PeLEDs can also be used in the field of quantum technologies by implementing a highly secure quantum random number generator (QRNG). Modern QRNGs that certify their privacy are posed to replace classical random number generators in applications such as encryption and gambling and therefore need to be cheap, fast, and with integration capabilities. Using a compact metal-halide PeLED source, we generate random numbers, which are certified to be secure against an eavesdropper, following the quantum measurement-device-independent scenario. The obtained generation rate of more than 10 Mbit s−1, which is already comparable to commercial devices, shows that PeLEDs can work as high-quality light sources for quantum information tasks, thus opening up future applications in quantum technologies.