WASHINGTON — In a significant technological advancement, researchers have unveiled a chip-based quantum random number generator that operates with high speed and quality on a miniaturized platform. This innovation could pave the way for integrating quantum random number generators into everyday devices, enhancing security without compromising speed.
The demand for true randomness is escalating due to the increasing need for secure online banking, private messaging, and protection of sensitive data from cyber threats. High-quality random numbers generated at rapid speeds are crucial for these applications.
“The quantum properties of light make it possible to produce numbers that are truly random, unlike the numbers generated by computer algorithms, which only imitate randomness,” said Raymond Smith, the research team leader from Toshiba’s Cambridge Research Laboratory in the United Kingdom. “However, making this technology practical for real-world use requires the optical components that create these quantum effects to be as small as possible so they can fit inside other systems.”
Technical Innovations and Challenges
Published in the Optica Publishing Group journal Optica Quantum, the researchers detailed a new design for a quantum random number generator. This design can recover the quantum signal even when obscured by noise, a challenge that has hindered chip-integrated devices. The device can generate unpredictable random numbers at a rate of 3 gigabits per second, meeting the security needs of large-scale data centers.
“A major application of random number generators is in protecting sensitive data and communications using encryption keys,” Smith explained. “Our technology can generate those keys at high speed and with strong security guarantees. High-speed random numbers are also critical for scientific simulations and artificial intelligence and for ensuring fairness in applications like online gaming or digital lotteries.”
Overcoming Noise in Miniaturized Systems
Integrated photonics, which employs tiny optical circuits on a chip, allows for the miniaturization of complex optical setups. However, these systems are sensitive to external disturbances such as electronic noise, which can degrade the quality of the quantum random numbers. Traditionally, recovering true quantum randomness required complex filtering, reducing the generation rate.
To address these challenges, the researchers developed a quantum random number generator that amplifies weak signals with an optical amplifier and uses a second photodiode to suppress crosstalk and other noise.
“Thanks to its built-in noise-rejection features, the photonic integrated circuit produces a much cleaner signal from the start, so it relies far less on heavy post-processing,” Smith noted. “This means we can keep the benefits of a miniaturized platform while still generating truly random numbers at high speed.”
Testing and Future Prospects
The researchers tested the new design by measuring the optical performance of the chip-based quantum random number generator in isolation. The circuit performed as expected, with the on-chip optical amplifier enhancing the quantum signal.
After packaging the chip and mounting it on a printed circuit board for operation alongside high-speed electronics, they observed electronic crosstalk. However, their dual-photodiode design minimized this interference. The system not only generated random numbers at 3 Gbps but also ran continuously for 24 hours, demonstrating excellent stability — a testament to using a single laser to maximize interference visibility.
Looking ahead, the researchers aim to increase the integration level between the optical and electronic components. “Our goal is to add more electronic functionality directly alongside the photonic chip, so the generator becomes as close as possible to a compact, standalone device,” Smith said. “This would make it easier to deploy in real-world systems and move it closer to commercial viability.”
Broader Implications and Industry Context
The announcement comes as the demand for secure digital communication continues to rise. The integration of quantum random number generators into commercial products could significantly enhance cybersecurity measures, providing a robust defense against increasingly sophisticated cyber threats.
Historically, the development of random number generators has been pivotal in encryption and secure communications. This breakthrough represents a crucial step toward realizing the full potential of quantum technology in everyday applications.
As the technology matures, it could also impact other fields, such as artificial intelligence and scientific research, where high-quality randomness is essential for simulations and modeling.
The research paper, titled “Noise-Rejecting Photonic Integrated Circuit for Robust Quantum Random Number Generation,” authored by P. R. Smith, D.G. Marangon, T.K. Paraiso, J.F. Dynes, and A. J. Shields, is available in the journal Optica Quantum with DOI: 10.1364/OPTICAQ.570625.
About the Publishing Entities
Optica Publishing Group, a division of the society Optica, is dedicated to advancing optics and photonics worldwide. It publishes a comprehensive collection of peer-reviewed content, including 18 prestigious journals and contributions from over 835 conferences.
Optica Quantum is an open-access journal focusing on high-impact results in quantum information science and technology, as enabled by optics and photonics. It maintains the same high standards for quality and significance as its parent journal, Optica, and is indexed in the Web of Science Emerging Sources Citation Index.
