Novel protocol for Quantum Key Distribution

ABSTRACT: Quantum key distribution (QKD) is an exciting application of quantum theory to the important real-world problem of secure communication. 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 and with information leakage from the classical communication channel required between the legitimate users can make it very difficult to guarantee security, or can have performance implications such as reducing the maximum key distribution distance. We will design and build a new type of QKD protocol that reduces the amount of classical communication required leading to new and more robust security models as well as greater efficiency. Quantum tools including a high speed single photon detection system and a source of entangled light will be developed to implement the protocol in an efficient way. BENEFIT: The technologies investigated in this proposal have a direct use in highly secure quantum key distribution systems. Such systems may benefit ultra-secure applications in the military, government, and private sector. The sub-components developed have other applications in fields such as imaging, metrology, and quantum computation. For instance, we will be developing single photon detectors that operate at rates more than an order of magnitude higher than the current commercially available equivalents. Such detectors may be useful in a variety of applications including deep-space communications, optical instrumentation, laser ranging, and spectroscopy.