Refining Quantum Cryptography

With its promise of security rooted in the laws of physics, quantum cryptography has seen tremendous growth as a worldwide research activity and the emergence of start-up commercial ventures since its invention 27 years ago. But in 2010, quantum hacking results (1, 2) appeared to call into question the validity of the entire endeavor. Instead, the ensuing vigorous debate, combined with major network testbed results in Japan (3) and China (4, 5), is defining a new, much brighter future for quantum crypto graphy research.