Novel protocol for Quantum Key Distribution

Quantum key distribution (QKD) is an exciting application of the quantum theory to the important real-world problem of secure communications. Specifically, QKD may allow for provably secure key distribution. These random keys can then be used either in a one-time-pad style encryption system (for absolute security at low rates) or a standard encryption system (for high security at high rates). Traditional means of distributing keys are not provably secure. The value of QKD thus rests in its unprecedented high level of security, so it is critical to maintain the integrity of the theoretical security advantage in any actual implementation. In practice, issues associated with non-ideal components used in protocol implementation, and with information leakage from the classical communication channel required between the legitimate users, can make it more difficult to guarantee security. They also reduce the key rate and the maximum key distribution distance. We propose to investigate a new protocol for QKD that reduces the burden on the classical communication channel leading to better efficiency and more security. We also investigate the use of emerging technologies for quantum state generation and detection which may also improve efficiency, reach, and security of the QKD systems. BENEFIT: The technologies investigated in this proposal have a direct use in practical and highly secure quantum key distribution systems. Such systems may benefit ultra-secure applications in the military, government, and the private sector. The sub-components developed have other applications in fields such as imaging, metrology, and quantum computation. For instance, we will be developing very fast single-photon detectors. Such detectors may be useful in a variety of applications including deep-space communications, optical instrumentation, laser ranging, and spectroscopy.