ÖAW research group uses quantum speed limit to generate certified random numbers

Unlike classical random number generators, whose outputs may appear random but could be predicted by the model, the QSL-based methods deliver verifiably unpredictable results, according to the team. "Das lässt sich durch ein klassisches Modell nicht erklären", Caroline Jones from the Müller group told the APA. "Wir erzeugen damit sicheren Zufall."

Certified randomness as a security building block

For security-critical applications such as encrypted communications or digital elections, a higher degree of reliability is needed than for simple random numbers, Jones emphasized. "Zertifiziert zufällige Zahlen, die nicht nur zufällig erscheinen, sondern nachweislich unvorhersehbar sind - selbst für Angreifer, die mehr über unsere Laborgeräte wissen als wir" - this is how she formulated the claim made of the method.

The principle takes up an old dispute in physics. "Ursprünglich wurde diese Unbestimmtheit in der Quantentheorie skeptisch gesehen (Albert Einstein: "Der Alte würfelt nicht"), doch spätestens Werner Heisenbergs Unschärferelation verankerte den probabilistischen Ansatz", the researchers write in the background.

Significance for cryptography and IT security

The practical demonstration forms the core of the publication. The IQOQI researchers were able to experimentally show that the bit strings obtained from a quantum system pass statistical tests and at the same time possess a certificate confirming their genuine randomness. This closes a gap between theoretical quantum mechanics and concrete application.

Müller and his team see the results as a contribution to next-generation cryptography. Conventional quantum computers could break many of the encryption methods used today; at the same time, methods based on quantum physical effects are being developed. Certified random numbers are considered an important building block in this context.

Outlook and open questions

The method could in the future be used in security-relevant areas such as government communications, financial transactions, or electoral systems. It remains open how the method can be scaled up to industrial dimensions and what standards would be required for certification.

The study is part of a series of international works aiming to harness quantum effects for IT security. While corporations such as IBM and Google are primarily working on quantum computers, academic groups such as the one at IQOQI are pursuing complementary applications, where the focus is not on computing power but on the fundamental unpredictability of nature.