Experimental Quantum Oblivious Transfer and Its Applications

Secure multiparty computation (MPC) enables computations across multiple users while preserving individual privacy and has a wide range of applications. MPC can be realized using oblivious transfer (OT) as a primitive function. Conventional OT protocols are based on mathematical assumptions such as discrete logarithm, which are vulnerable to quantum attacks. Quantum oblivious transfer (QOT), assuming the existence of additional functionality primitives, offers a quantum-secure alternative. This study experimentally implements a quantum secure QOT protocol that surpasses the noisy storage model using a bit commitment scheme. Then, this QOT protocol is applied to solve the Yao’s Millionaires’ Problem, which is a typical example of secure multi-party computation, where two parties aim to compare the size of their private inputs without revealing any additional information.