From securing online accounts to ensuring fairness in public lotteries, the generation of unpredictable numbers is a cornerstone of modern technology and society. For decades, however, a fundamental problem has persisted: how can you be certain that a random number is truly random and not the product of a rigged or predictable system? Classical computers can only produce “pseudorandom” numbers, which follow a complex algorithm that could theoretically be predicted. Addressing this challenge, researchers have developed a new type of random number generator that leverages the inherent unpredictability of quantum physics and verifies its results using cutting-edge cryptography, according to new research published in the journal Nature (1, 2).

At the core of the new system lies quantum entanglement, a phenomenon Albert Einstein famously called “spooky action at a distance.” Researchers at the National Institute of Standards and Technology (NIST) and their colleagues generate pairs of entangled photons, or light particles. These photons are intrinsically linked, meaning that a measurement of one particle instantly influences the other, regardless of their spatial separation. The outcome of each measurement is entirely random, a fundamental rule of the universe. By performing an experiment known as a Bell test on these photon pairs, the scientists can not only generate random bits but also prove that the randomness comes from this non-local quantum effect, ruling out any hidden classical influence.

While quantum mechanics provides the raw randomness, the researchers needed a way to make the entire process transparent and tamper-proof. To achieve this, they developed a novel protocol that acts like a public ledger. Using a cryptographic method inspired by blockchain technology, each step in the generation and processing of the random numbers is marked with a “hash,” a unique digital fingerprint. These hashes are then linked together in a chain, creating a verifiable and auditable record. If any data is altered at any point, the digital fingerprints will no longer match, immediately revealing the manipulation. This intertwined chain ensures that the final random numbers are certifiably traced back to their quantum origin.

The result of this work is a publicly accessible quantum randomness beacon that provides a stream of certifiably random bits for anyone to use. Over its first 40 days of operation, the system successfully generated 512-bit strings of random numbers with a 99.7% success rate. This marks a significant milestone, as it creates a public service that operates with a provable quantum advantage over conventional methods. The traceable and verifiable nature of these numbers makes them ideal for high-stakes applications requiring ultimate fairness and security, including cryptographic key generation, scientific simulations, and the selection of participants in clinical trials or public audits.

References

• Kavuri, G. A., Palfree, J., Reddy, D. V., Zhang, Y., Bienfang, J. C., Mazurek, M. D., Alhejji, M. A., Siddiqui, A. U., Cavanagh, J. M., Dalal, A., Abellán, C., Amaya, W., Mitchell, M. W., Stange, K. E., Beale, P. D., Brandão, L. T. A. N., Booth, H., Peralta, R., Nam, S. W., … Shalm, L. K. (2025). Traceable random numbers from a non-local quantum advantage. Nature, 642(8069), 916–921. https://doi.org/10.1038/s41586-025-09054-3

• Brown, P. (2025). Cheat-proof random numbers generated from quantum entanglement. Nature, 642(8069), 875–876. https://doi.org/10.1038/d41586-025-01451-y
• National Institute of Standards & Technology. (2025, June 11). Quantum mechanics provide truly random numbers on demand. Phys.Org; National Institute of Standards & Technology. https://phys.org/news/2025-06-quantum-mechanics-random-demand.html