One way quantum bit commitment through classical correlation
Abstract
A one way partial quantum bit commitment protocol is developed, using states with built-in classical correlation, completely independent of entanglement. It involves concealing information in a set of mutually non-orthogonal states and revealing it through measurements on a set of product states that are mutually orthogonal. Given 2N choices to commit from, the protocol encodes each choice in a N+1 qubit state, from 2N non-orthogonal states. A previously agreed upon N qubit state corresponding to each choice, when coupled with the N+1 qubit state, yields an element belonging to a set of orthogonal product states, which can be deterministically distinguished. The protocol is demonstrated by implementing it for a `coin-toss' game. A procedure to enhance security of the protocol is explicated, increasing the number of qubits required. Thus a modification is suggested to reduce this required number.