ETH Zurich scientists create perfect randomness for the first time

ETH Zurich researchers Renato Renner and Andreas Wallraff demonstrated the first method to generate perfect, certifiably unpredictable randomness using quantum physics, published in Nature in May 2026. Their breakthrough leverages quantum mechanics to amplify weak random inputs into fully unbiased bit strings, eliminating bias inherent in classical randomness generation methods. The team’s approach ensures the output is not just statistically random but fundamentally unpredictable, addressing a long-standing challenge in cryptography and quantum computing. This advancement provides a rigorous foundation for ultra-secure encryption, quantum simulations, and algorithms requiring true randomness, where even slight biases can compromise results. The work marks a milestone in quantum information science, offering a provably reliable source of randomness for next-generation technologies dependent on absolute unpredictability.