Bidirectional secret communication by quantum collisions

Abstract

A novel secret communication protocol based on quantum entanglement is introduced. We demonstrate that Alice and Bob can perform a bidirectional secret communication exploiting the "collisions" on linear optical devices between partially shared entangled states. The protocol is based on the phenomenon of coalescence and anti-coalescence experimented by photons when they are incident on a 50:50 beam splitter. © 2009 Springer-Verlag Berlin Heidelberg.