General Properties of Quantum Bit Commitment.

Jun Yan

Anthony J. Short, Nicolas Gisin, Sandu Popescu

Yaqi Song, Li Yang

A semi-counterfactual quantum bit commitment (SCQBC) protocol is presented here for the first time, which makes use of counterfactual property. Similar to a counterfactual quantum key distribution scheme, half-photons are not transmitted through the quantum channel in our proposed protocol. In the SCQBC protocol, Bob, the verification party of the quantum bit commitment (QBC), sends the states while Alice, the commitment party, receives. Since Alice cannot receive all the states and entangle the commit bits with the verifier's registers, it is not subject to Mayers' and Lo-Chau's no-go theorem. In addition, a general bit commitment framework can be extracted from the SCQBC scheme, which opens up a new class of cryptographic protocols in counterfactual cryptography.

Jeffrey Bub

S. N. Molotkov, S. S. Nazin

Under rather general assumptions about the properties of a quantum channel with noise, a quantum protocol providing implementation of secret bit commitment with the probability as close to unity as is wished is proposed.

S. N. Molotkov, S. S. Nazin

Under rather general assumptions about the properties of a noisy quantum channel, a first quantum protocol is proposed which allows to implement the secret bit commitment with the probability arbitrarily close to unity.