An ETH Zurich team led by cryptographer Renato Renner linked 2 qubits over 30 meters to generate certified randomness that no machine can predict. The researchers used quantum entanglement and a two-source extractor technique to produce a stream of numbers certified by physics rather than hardware assumptions, with findings published in Nature. The experiment addresses cryptography, gaming, and security applications by providing unpredictability anchored to quantum mechanics rather than classical pseudo-random algorithms. The work builds on Bell test research that rules out hidden classical variables, offering what the team calls a "perfect die" whose outputs remain fundamentally unknowable. The result strengthens the case for quantum advantage in security systems and challenges deterministic models of reality by demonstrating that certain outcomes are provably beyond prediction.
ETH Zurich Team Demonstrates Certified Quantum Randomness Using Entangled Qubits
The ETH Zurich experiment entangled 2 qubits using microwave photons across roughly 98 feet inside a 30-meter tunnel in Zurich. Measurements on one qubit correlated with the other, but individual outcomes remained fundamentally unknowable according to the team. Raw results from those measurements were processed with a two-source extractor, a technique that purifies weakly random inputs into provably random outputs. The claim rests on physics rather than trusting the device's internals, with randomness certified by the experiment's structure and quantum theory itself. The work appears in Nature and leans on decades of Bell test research that rules out hidden classical variables.
Cryptography and Gaming Applications Emerge from Physics-Backed Entropy
The approach differs from typical generators that rely on algorithms or environmental noise by anchoring output to the laws of quantum mechanics. The immediate target is cryptography, where key security depends on unpredictability. Banks, cloud providers, and hardware security modules could feed these certified bits into key generation, secure boot, and high-stakes authentication according to the researchers. Gaming and lotteries are candidates, though scaling and cost will decide the pace. The researchers frame the result as evidence of quantum advantage, a domain where classical machines cannot match the guarantee. For developers and CISOs, physics-backed entropy can raise the floor under security architectures that depend on pseudo-random seeds.
Quantum Mechanics Challenges Determinism Through Provably Unpredictable Outputs
The result addresses a long-running debate in physics. If certain outputs are provably beyond prediction, then indeterminacy is baked into reality rather than representing ignorance. That supports the probabilistic view of quantum mechanics and narrows the room for hidden-determinist explanations according to the team. The finding reframes risk models by demonstrating that some uncertainty cannot be averaged away, only respected and harnessed.
FAQ
What did the ETH Zurich team achieve with entangled qubits?
The ETH Zurich team led by Renato Renner linked 2 qubits over 30 meters to generate certified randomness using quantum entanglement and a two-source extractor. The system outputs bits no one can predict, with randomness certified by physics rather than hardware assumptions, and findings were published in Nature.
How does quantum randomness differ from traditional random number generators?
Quantum randomness is anchored to the laws of quantum mechanics rather than relying on algorithms or environmental noise. The ETH Zurich approach uses entangled qubits and a two-source extractor to produce provably random outputs certified by the experiment's structure and quantum theory, building on Bell test research that rules out hidden classical variables.
Why does certified quantum randomness matter for cryptography?
Certified quantum randomness provides unpredictability that no machine can second-guess, which is critical for cryptographic key security. Banks, cloud providers, and hardware security modules could use these physics-backed bits for key generation, secure boot, and authentication, raising the security floor under architectures that currently depend on pseudo-random seeds.
