Perfect Randomness Realized For the First Time
Source: Slashdot
Overview
Researchers at ETH Zurich have generated certified “perfect randomness” for the first time using a quantum Bell‑test setup with two entangled superconducting chips linked by a 30‑meter cooled connection. The work, reported by Phys.org, could become a cornerstone for digital security, analogous to the role of atomic clocks in timekeeping.
Method: Randomness Amplification
The team employed a technique called randomness amplification. By improving the Bell‑test to achieve both high quality and high data rate, they were able to certify the randomness of the output bits.
Experimental Setup
- Superconducting chips: Two chips, each acting as a qubit, were cooled to temperatures near absolute zero.
- 30‑meter cooled link: A tube connecting the chips allows microwave photons to travel back and forth, establishing quantum entanglement.
- Measurement basis: The choice of measurement basis for each qubit was driven by an imperfect random number generator.
Because the chips are separated by 30 m, any signal traveling at the speed of light cannot influence the other chip during the measurement, preserving the integrity of the randomness.
Results
Renato Renner and Andreas Wallraff’s team showed that the measurement outcomes—strings of 0s and 1s—are perfectly random and can be certified. Renner described the achievement as crossing a ridge: the improvements now allow the creation of random numbers that remain perfectly random “for all eternity,” regardless of the analytical methods applied to test them.
Potential Applications
- Encryption of sensitive communications and digital identities
- Public randomness services for lotteries
- Blockchain and other distributed ledger technologies
Publication
The findings were published in Nature.
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