Quantum Laser Generates 2.0 Gigabits of Random Data Per Second

Until now, generating truly random numbers at high speed has relied on complex systems or algorithms with inherent limitations. Now, engineers have created a quantum random number generator, a QRNG, based on the natural quantum behaviour of a single-frequency laser, achieving a raw data rate of 2.0 Gbps. This new device successfully passed rigorous statistical tests, confirming the randomness of the numbers it produces and attaining a post-processed rate of 1.0 Gbps.

Researchers have engineered a quantum random number generator, a QRNG, capable of producing truly random numbers at a rate of 1.0 Gbps following data processing. These QRNGs exploit the unpredictable nature of quantum mechanics, offering a fundamentally secure alternative to traditional methods reliant on algorithms or physical processes. Achieving a Technology Readiness Level of 7 signifies the system is advanced enough for deployment in practical applications like secure communications and detailed simulations; it is nearing full operational status. The significance of reaching TRL 7 cannot be overstated, as it indicates the technology has moved beyond theoretical proof-of-concept and is demonstrably viable for integration into real-world systems, requiring minimal further development before deployment. This is particularly important for security-critical applications where trust in the randomness source is paramount.

Scientists are developing increasingly sophisticated methods for generating truly random numbers, essential for fields ranging from cryptography to complex simulations. Current systems often rely on algorithms or physical processes that, while appearing random, are ultimately predictable; however, quantum random number generators, or QRNGs, harness the inherent unpredictability of quantum mechanics to provide a fundamentally secure alternative. A self-heterodyne measurement, for example, is akin to carefully listening for subtle differences between two nearly identical musical notes to detect even the smallest variation. Engineers have now created a QRNG based on a single-frequency laser, achieving a post-processed data rate of 1.0 Gbps and attaining Technology Readiness Level 7, indicating it is nearing full operational status. This advancement promises a robust solution for applications demanding high-speed, verifiable randomness, but can this technology be scaled to meet the growing demands of global data security. The demand for high-quality random numbers is escalating due to the increasing prevalence of encryption, Monte Carlo simulations in finance and physics, and the growing field of machine learning, where randomness is crucial for model training and preventing bias.

High-speed quantum randomness now reaches technology readiness level seven

A new quantum random number generator (QRNG) achieves a raw data generation rate of 2.0 Gbps, surpassing previous limitations imposed by complex systems and algorithms. Attaining a Technology Readiness Level (TRL) of 7 signifies the system is advanced enough for real-world deployment, a milestone previously elusive for high-speed QRNGs confined to laboratory settings. This phase-noise-based QRNG exploits the unpredictable quantum behaviour of a single-frequency laser, translating quantum jitter into truly random numbers validated by both NIST and Diehard test suites. The NIST Statistical Test Suite and Diehard tests are comprehensive collections of statistical tests designed to assess the quality of random number generators, ensuring they meet stringent criteria for randomness and lack of bias. Passing these tests is a crucial validation step for any QRNG intended for security applications.

Sustaining a post-processed rate of 1.0 Gbps, the QRNG offers a viable solution for applications requiring verifiable randomness, ranging from cryptography to detailed simulations. It utilizes a self-heterodyne measurement technique, employing a semiconductor laser with a linewidth of approximately 5.23GHz and a 48cm fibre delay line to amplify quantum effects. The device also achieved a Technology Readiness Level of 7, demonstrating progression beyond purely laboratory experimentation and towards practical application, enabled by in-house developed extraction techniques like the Toeplitz Strong Extractor. While currently outputting 1.0 Gbps, the achievable generation rate is limited by the Field Programmable Gate Array’s output interface, meaning sustained multi-gigabit streaming requires upgrades to components such as PCIe or SFP connections. The Toeplitz Strong Extractor is a specific type of randomness extractor, a crucial component in QRNGs that removes any residual correlations or biases in the raw quantum data, ensuring the output is truly random and suitable for cryptographic applications. The linewidth of the laser, at 5.23GHz, is a key parameter influencing the amount of quantum noise available for random number generation; a narrower linewidth generally indicates a more stable laser but potentially less noise, while a wider linewidth provides more noise but requires more sophisticated processing to extract the randomness. The 48cm fibre delay line introduces a time delay between two copies of the laser signal, enabling the self-heterodyne measurement to detect phase differences and amplify the quantum noise.

Demonstrating gigabit per second quantum random number generation with current limitations

Ever more robust random number generation is crucial for securing digital information, driving innovation beyond the limitations of traditional computational approaches. Quantum Random Number Generators, or QRNGs, utilise the unpredictable nature of quantum physics to create genuinely random digits, unlike their predictable counterparts, Pseudo-Random Number Generators. This technology, harnessing the unpredictable nature of light, will likely underpin stronger encryption methods in the coming decade. Pseudo-Random Number Generators (PRNGs) rely on deterministic algorithms, meaning that given the same initial seed, they will always produce the same sequence of numbers. This predictability makes them vulnerable to attacks if the seed is compromised. QRNGs, on the other hand, leverage the inherent randomness of quantum phenomena, providing a source of truly unpredictable numbers.

Conventional methods struggle to provide the unpredictability required for strong security protocols, making this advancement vital. This device delivers a practical quantum random number generator, achieving a post-processed data rate of 1.0 Gbps and reaching Technology Readiness Level 7. Quantum jitter is translated into genuinely random numbers, validated by established statistical tests, by exploiting the unpredictable quantum phase noise of a single-frequency laser. The core of this innovation lies in a self-heterodyne measurement, a technique that carefully detects minute variations in light waves to amplify quantum effects, allowing for the extraction of randomness from the quantum realm and conversion into digital data. The phase noise, a random fluctuation in the phase of the laser light, is the fundamental source of randomness in this QRNG. By precisely measuring these phase fluctuations, the device can generate a stream of random bits. The self-heterodyne technique involves interfering the laser light with a delayed copy of itself, creating a beat signal whose frequency fluctuates due to the quantum phase noise. This beat signal is then digitised and processed to extract the random numbers.

The researchers successfully developed a high-speed quantum random number generator utilising the quantum phase noise of a single-frequency laser. This is important because it provides a source of genuinely unpredictable numbers, unlike traditional methods which can be vulnerable to attack if compromised. The system achieved a post-processed data rate of 1.0 Gbps and reached Technology Readiness Level 7, indicating its suitability for real-time secure applications. The authors are continuing to refine the system, aiming to reach Technology Readiness Level 8 and further improve its performance.