Certified randomness using a trapped-ion quantum processor.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 40140579.
- Also identified by DOI 10.1038/s41586-025-08737-1 and PMC identifier 11981928.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Although quantum computers can perform a wide range of practically important tasks beyond the abilities of classical computers<sup>1,2</sup>, realizing this potential remains a challenge. An example is to use an untrusted remote device to generate random bits that can be certified to contain a certain amount of entropy<sup>3</sup>. Certified randomness has many applications but is impossible to achieve solely by classical computation. Here we demonstrate the generation of certifiably random bits using the 56-qubit Quantinuum H2-1 trapped-ion quantum computer accessed over the Internet. Our protocol leverages the classical hardness of recent random circuit sampling demonstrations<sup>4,5</sup>: a client generates quantum 'challenge' circuits using a small randomness seed, sends them to an untrusted quantum server to execute and verifies the results of the server. We analyse the security of our protocol against a restricted class of realistic near-term adversaries. Using classical verification with measured combined sustained performance of 1.1 × 10<sup>18</sup> floating-point operations per second across multiple supercomputers, we certify 71,313 bits of entropy under this restricted adversary and additional assumptions. Our results demonstrate a step towards the practical applicability of present-day quantum computers.