53 research outputs found
Low Cost and Compact Quantum Cryptography
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.Comment: 18 pages, 9 figures, to be published in New Journal of Physic
Experimental quantum key distribution secure against malicious devices
The fabrication of quantum key distribution (QKD) systems typically involves
several parties, thus providing Eve with multiple opportunities to meddle with
the devices. As a consequence, conventional hardware and/or software hacking
attacks pose natural threats to the security of practical QKD. Fortunately, if
the number of corrupted devices is limited, the security can be restored by
using redundant apparatuses. Here, we report on the demonstration of a secure
QKD setup with optical devices and classical post-processing units possibly
controlled by an eavesdropper. We implement a 1.25 GHz chip-based
measurement-device-independent QKD system secure against malicious devices on
\emph{both} the measurement and the users' sides. The secret key rate reaches
137 bps over a 24 dB channel loss. Our setup, benefiting from high clock rate,
miniaturized transmitters and a cost-effective structure, provides a promising
solution for widespread applications requiring uncompromising communication
security.Comment: 28 pages, 5 figures, 4 table
- …