Unconditionally secure quantum bit commitment is simply possible

Abstract

Mayers, Lo and Chau proved unconditionally secure quantum bit commitment is impossible. It is shown that their proof is valid only for a particular model of quantum bit commitment encoding, in general it does not hold good. A different model of unconditionally secure quantum bit commitment - both entanglement and disentanglement-based - is presented. Even cheating can be legally proved with some legal evidences. Unconditionally secure quantum bit commitment can be established on the top of unconditionally secure quantum coin tossing, which is also claimed to be two-way impossible.