We propose a practical quantum oblivious transfer and a bit commitment protocols which replace the single-photon source with weak coherent pulses and allow error and loss in channel and detectors. These protocols can be realized with available optoelectronic apparatus.
Oblivious transfer (OT) and bit commitment (BC) are two-party cryptographic protocols which play crucial roles in the construction of various cryptographic protocols. We propose three practical quantum cryptographic protocols in this paper. We first construct a practical quantum random oblivious transfer (R-OT) protocol based on the fact that non-orthogonal states cannot be reliably distinguished. Then, we construct a fault-tolerant one-out-of-two oblivious transfer ( O T 1 2 ) protocol based on the quantum R-OT protocol. Afterwards, we propose a quantum bit commitment (QBC) protocol which executes the fault-tolerant O T 1 2 several times. Mayers, Lo and Chau (MLC) no-go theorem proves that QBC protocol cannot be unconditionally secure. However, we find that computing the unitary transformation of no-go theorem attack needs so many resources that it is not realistically implementable. We give a definition of physical security for QBC protocols and prove that the practical QBC we proposed is physically secure and can be implemented in the real world.
Among the most studied tasks in Quantum Cryptography one can find Bit Commitment (BC) and Oblivious Transfer (OT), two central cryptographic primitives. In this paper we propose for the first time protocols for these tasks in the measurement-device independent (MDI) settings and analyze their security. We analyze two different cases: first we assume the parties have access to perfect single photon sources (but still in the presence of noise and losses), and second we assume that they only have imperfect single photon sources. In the first case we propose a protocol for both BC and OT and prove their security in the Noisy Quantum Storage model. Interestingly, in the case where honest parties do not have access to perfect single photon sources, we find that BC is still possible, but that it is "more difficult" to get a secure protocol for OT: We show that there is a whole class of protocols that cannot be secure. All our security analyses are done in the finite round regime.
We present a new simulation-secure quantum oblivious transfer (QOT) protocol based on one-way functions in the plain model. With a focus on practical implementation, our protocol surpasses prior works in efficiency, promising feasible experimental realization. We address potential experimental errors and their correction, offering analytical expressions to facilitate the analysis of the required quantum resources. Technically, we achieve simulation security for QOT through an e q u i v o c a l and r e l a x e d − e x t r a c t a b l e quantum bit commitment.