Система Two-Qubit производит сертифицированную случайность для безопасных ключей

A Swiss team entangled two qubits 30 m apart and ran 1.5 billion Bell tests, producing certifiably random numbers that could underwrite future encryption schemes.

Quantum‑Generated Randomness

Randomness is the linchpin of modern cryptography. Conventional electronic devices generate pseudo‑random bits by deterministic circuits, leaving subtle patterns that attackers can exploit. Quantum mechanics, by contrast, offers intrinsic unpredictability: a qubit exists in a superposition of states until measured, collapsing into a single outcome that is fundamentally random.

The Experiment

Renner, a physics professor at ETH Zurich, and colleague Andreas Wallraff built a 30‑meter‑long cryogenic tube to house two superconducting qubits at temperatures near absolute zero. The distance ensured no classical signal could influence both ends, satisfying the locality requirement of a Bell test. They entangled the qubits so that measuring one instantly determined the state of the other.

Running roughly 1.5 billion Bell tests, the team collected a stream of outcomes that, when fed into a custom algorithm, yielded a sequence of bits that passed all statistical randomness checks. In a side experiment, they fed a photograph of a sheep into the system; the resulting color pattern was irreproducible, even by a quantum computer.

Implications for Encryption

The study, published in Nature, marks the first demonstration of a practical, verifiable source of quantum randomness that can be scaled. Cryptographic protocols—whether current RSA or future post‑quantum schemes—depend on high‑quality random keys. Imperfect randomness has historically enabled attacks; this work removes that vulnerability.

While commercial quantum computers remain years away, the infrastructure described here can be integrated into existing hardware. By generating keys on demand with provable randomness, systems can resist both classical brute‑force attempts and future quantum‑powered adversaries.

Future work will focus on reducing the physical footprint and increasing the bit‑rate, but the core insight is clear: a two‑qubit entangled system can deliver the kind of randomness that modern encryption desperately needs.

Source: A quantum computing system's perfect randomness could keep your secrets safe
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