59 research outputs found
High-dimensional Encoding in the Round-Robin Differential-Phase-Shift Protocol
In quantum key distribution (QKD), protocols are tailored to adopt desirable
experimental attributes, including high key rates, operation in high noise
levels, and practical security considerations. The round-robin differential
phase shift protocol (RRDPS), falling in the family of differential phase shift
protocols, was introduced to remove restrictions on the security analysis, such
as the requirement to monitor signal disturbances. While the RRDPS protocol
requires the encoding of single photons in high-dimensional quantum states, at
most, only one bit of secret key is distributed per sifted photon. However,
another family of protocols, namely high-dimensional (HD) QKD, enlarges the
encoding alphabet, allowing single photons to carry more than one bit of secret
key each. The high-dimensional BB84 protocol exemplifies the potential benefits
of such an encoding scheme, such as larger key rates and higher noise
tolerance. Here, we devise an approach to extend the RRDPS QKD to an
arbitrarily large encoding alphabet and explore the security consequences. We
demonstrate our new framework with a proof-of-concept experiment and show that
it can adapt to various experimental conditions by optimizing the protocol
parameters. Our approach offers insight into bridging the gap between seemingly
incompatible quantum communication schemes by leveraging the unique approaches
to information encoding of both HD and DPS QKD.Comment: 10 pages, 6 figure
- …