top of page



The principles of quantum mechanics offer a ground-breaking path towards achieving unconditional security in information exchange. This level of security, also known as perfect, or information-theoretic security (i.t.-security), drives numerous applications, including quantum key distribution and the development of a quantum internet. However, for decades, it was unclear whether it would ever be possible that the fundamental laws of quantum physics extend their protective umbrella to secure digital payments, such that a level of payment security is attained that resists attacks from quantum computers or even computers with unlimited computational power?

Thanks to the ground-breaking research of QUBO scientists and researchers at the University of Vienna, an i.t.-secure scheme based on quantum-tokenized technology  has been developed. This method imprints sensitive data onto a specially prepared stream of single photons that serve as quantum tokens. Thanks to the no-cloning principle of quantum mechanics, it is impossible to counterfeit such tokens, and they can only be used once. Any malicious attempts to tamper with desired communication protocols are easily detectable by the token provider without leakage of the sensitive information data.

The photonic quantum tokenization platform opens various application areas, prominently in the payment industry, which we pursue in the context of 

QUBO PayTech.


Demonstration of quantum-digital payments

P. Schiansky, J. Kalb, E. Sztatecsny, M.-C. Roehsner, T. Guggemos, A. Trenti, M. Bozzio, P. Walther


Nature Communications 14, 3849 (2023)

Digital payments have replaced physical banknotes in many aspects of our daily lives. Similarly to banknotes, they should be easy to use, unique, tamper-resistant and untraceable, but additionally withstand digital attackers and data breaches. Current technology substitutes customers’ sensitive data by randomized tokens, and secures the payment’s uniqueness with a cryptographic function, called a cryptogram. However, computationally powerful attacks violate the security of these functions. Quantum technology comes with the potential to protect even against infinite computational power. Here, we show how quantum light can secure daily digital payments by generating inherently unforgeable quantum cryptograms. We implement the scheme over an urban optical fiber link, and show its robustness to noise and loss-dependent attacks. Unlike previously proposed protocols, our solution does not depend on long-term quantum storage or trusted agents and authenticated channels. It is practical with near-term technology and may herald an era of quantum-enabled security.

For full article please refer to


Probabilistic one-time programs using quantum entanglement

 M.-C. Röhsner, J. A. Kettlewell, J. Fitzsimons, P. Walther


npj Quantum Information 7, 98 (2021)

Quantum technology allows for unparalleled levels of data and software protection. Probabilistic one-time programs harness these capabilities for quantum-assisted classical computations by encoding classical software in small quantum states resulting in computer programs that can be used only once. Such self-destructing one-time programs facilitate a variety of applications reaching from software distribution to one-time delegation of signature authority. Whereas previous experiments demonstrated the feasibility of such schemes, the practical applications were limited. Here we present an improved protocol for one-time programs that resolves major drawbacks of previous schemes, by employing entangled qubit pairs. This results in four orders of magnitude higher count rates and the ability to execute a program long after the quantum information exchange has taken place. We implement a one-time delegation of signature authority over an underground fiber link between university buildings in downtown Vienna, emphasizing the compatibility of our scheme with prepare-and-measure quantum internet networks.

For full article please refer to


bottom of page