Secure multi-party biometric verification using QKD assisted quantum oblivious transfer

We present an experimentally feasible implementation of a secure multiparty computation application enabled by quantum oblivious transfer (QOT) on an entanglement-based physical layer. The QOT protocol uses polarization-encoded entangled states to share oblivious keys between two parties with quantum key distribution (QKD) providing authentication. Our system integrates the post-processing for QOT and QKD, both sharing a single physical layer, ensuring efficient key generation and authentication, respectively. Authentication involves hashing messages into a cryptographic context, verifying tags, and replenishing keys. This process uses a parallel QKD pipeline specifically for authentication, not for secure key generation. Oblivious keys are generated over a distance up to 25.8 km with a channel loss of 8.47 dB. In a back-to-back setup, a QOT rate of Formula: see text OTs/second is achieved, corresponding to 1 minute and 53 seconds per OT, primarily limited by the entanglement source. Using pre-distributed oblivious keys improved the rate to 0.11 OTs/second, or 9.1 seconds per OT. The considered QOT protocol is statistically correct, computationally secure for an honest receiver, and statistically secure for an honest sender, assuming a computationally hiding, statistically binding commitment. An experimentally feasible use case is demonstrated for privacy-preserving fingerprint matching against no-fly lists for border control. The fingerprint is secret-shared across two sites, ensuring security, while the matching is performed using the MASCOT protocol, supported by QOT. The application required 128 1-out-of-2 OTs, each with message length of 128 bits, with the highest security achieved in 20 minutes and 39 seconds. This work demonstrates the feasibility of QOT in secure quantum communication applications.