  Entanglement is essential to many quantum information applications, but it is
easily destroyed by quantum decoherence arising from interaction with the
environment. We report the first experimental demonstration of an
entanglement-based protocol that is resilient to loss and noise which destroy
entanglement. Specifically, despite channel noise 8.3 dB beyond the threshold
for entanglement breaking, eavesdropping-immune communication is achieved
between Alice and Bob when an entangled source is used, but no such immunity is
obtainable when their source is classical. The results prove that entanglement
can be utilized beneficially in lossy and noisy situations, i.e., in practical
scenarios.
