Cheat-proof random numbers generated from quantum entanglement

Piotr Paweł Jóźwiak

Horace P. Yuen

The ``impossibility proof'' on unconditionally secure quantum bit commitment is examined. It is shown that the possibility of juxtaposing quantum and classical randomness has not been properly taken into account. A specific protocol that beats entanglement cheating with entanglement is proven to be unconditionally secure.

Nicolò Leone, Stefano Azzini, Sonia Mazzucchi +1 more

In this work we present a proof-of-concept of a photonic quantum random number generation scheme based on the entanglement between two internal degrees of freedom of single photons. The quantum correlations between momentum and polarization at the single photon level are verified by a Bell test in the CHSH form. The violation of this inequality not only ensures the entanglement, but also provides an estimation of the minimum entropy of the generated sequence. This allows to optimize the application of randomness extractor to obtain an unbiased sequence of random numbers.

Christian Kollmitzer, Stefan Schauer, Stefan Raß +1 more

Horace P. Yuen

Bit commitment involves the submission of evidence from one party to another so that the evidence can be used to confirm a later revealed bit value by the first party, while the second party cannot determine the bit value from the evidence alone. It is widely believed that secure quantum bit commitment is impossible due to quantum entanglement cheating, which is codified in a general impossibility theorem. In this paper, the scope of this general impossibility proof is extended and analyzed, and gaps are found. Three specific protocols are described for which the entanglement cheating as given in the impossibility proof fails to work. One of these protocols, QBC2, is proved to be unconditionally secure.

Christian Kollmitzer, Stefan Petscharnig, Martin Suda +1 more