Low cost and compact quantum key distribution

Abstract

We present the design of a novel free-space quantum cryptography system, complete with purpose-built software, that can operate in daylight conditions. The transmitter and receiver modules are built using inexpensive off-the-shelf components. Both modules are compact allowing the generation of renewed shared secrets on demand over a short range of a few metres. An analysis of the software is shown as well as results of error rates and therefore shared secret yields at varying background light levels. As the system is designed to eventually work in short-range consumer applications, we also present a use scenario where the consumer can regularly 'top up' a store of secrets for use in a variety of one-time-pad and authentication protocols.

Orbital angular momentum vertical-cavity surface-emitting lasers

“…The VCSEL device represents an attractive light source in many industrial applications due to its low fabrication cost, high energy efficiency, circularly symmetric beam profile, and high intrinsic modulation bandwidths [13,14]. There has also been intense research into the use of VCSEL-like devices as singlephoton sources [15] and as low-cost sources in quantum key distribution (QKD) systems [16]. By integrating VCSELs with our additional phase structures, high-purity OAM modes and their superposition states can be generated while maintaining advantages in cost and power efficiency.…”

Air to ground quantum key distribution

“…The idea is somehow similar to one time transaction authentication numbers (TANs) as used today only that the key length could be much longer (the necessity to type the key by hand drops) and the secure quantum distribution replaces the TAN letter. The development of such hand held QKD systems started already in 2006 [121] and with recent advances in wave guide optics becomes more and more feasible.…”

Quantum-Classical Access Networks with Embedded Optical Wireless Links

“…Embedding QKD capability onto mobile devices is considered as an attractive solution for exchanging sensitive data in a safe and convenient manner, particularly in indoor environments [10]. For instance, customers in a bank can exchange secret keys wirelessly with access points in the branch without waiting for a teller or a cash machine.…”