ETH Zurich Generates First Certifiably Perfect Random Numbers Using Entangled Superconducting Qubits and Bell Test

Researchers at ETH Zurich have, for the first time, generated certifiably perfect random numbers using a quantum experiment involving entangled superconducting qubits. Led by Renato Renner and Andreas Wallraff in the Department of Physics, the work employs randomness amplification via an improved Bell test to overcome systematic biases inherent in conventional generators. The results, published in the journal Nature, establish a physically certified source of randomness for cryptographic and security applications.

Technical Design & Implementation Specifications

The experimental setup comprises two superconducting chips, each implementing a quantum bit (qubit) cooled to temperatures near absolute zero. A 30-meter-long cooled tube connects the chips, enabling microwave photons to establish quantum entanglement between the qubits. The exact measurement basis applied to each qubit is selected using an imperfect classical random number generator; a dedicated algorithm then amplifies the resulting measurement outcomes into certifiably perfect bit strings.

Key parameters include:

• Two superconducting qubits on separate chips
• 30-meter entanglement link via microwave photons
• Improved Bell test achieving simultaneously high quality and high data rate
• 30-meter separation to preclude light-speed information exchange during measurement

This architecture guarantees that quantum correlations certify the output randomness independent of any device imperfections.

Commercial Outlook & Industry Integration

The certified randomness source addresses a long-standing limitation in digital security, where even minor biases in random number generators can compromise encryption strength. In the long term, the approach is positioned to function as a foundational standard for digital security—analogous to atomic clocks for timekeeping—supporting encryption of sensitive communications, digital identities, public randomness services for lotteries and blockchain, and quantum-secure communication systems.

By providing mathematically verifiable perfect randomness, the technology enhances the robustness of cryptographic protocols and supports broader adoption of quantum-secure infrastructures across finance, government, and enterprise sectors.

Find out more here. Further articles, reports, and the latest quantum computing news may be found at The Qubit Report.