Publications: Quantum cryptography

Security of differential phase shift QKD from relativistic principles
with Martin Sandfuchs, Martin Haberland, and V. Vilasini

20 years after its invention, we provide a full security proof of the differential phase shift protocol for quantum key distribution! The proof combines the entropy accumulation theorem with relativistic principles and techniques from quantum optics.

ArXiv: 2301.11340

Quantum advantage in cryptography
with Renato Renner

We give an overview of the principles of quantum mechanics that enable information-theoretic security, why quantum cryptography is important, and discuss the state of the art of the field.

Journal: AIAA Journal, 1–16
ArXiv: 2206.04078

Device‑independent quantum key distribution with random key basis
with René Schwonnek, Koon Tong Goh, Ignatius W. Primaatmaja, Ernest Y.-Z. Tan, Valerio Scarani, and Charles C.-W. Lim

We present a simple variant of the original device-independent QKD protocol based on the CHSH inequality that uses for two randomly chosen key generating bases instead of one. This enables positive key rates in the high-noise regimes and significantly narows the gap between theory and experiment.

Journal: Nature Communications 12, 2008 (2021)
ArXiv: 2005.02691

Entanglement detection by violations of noisy uncertainty relations: A proof of principle
with Yuan-Yuan Zhao, Guo-Yong Xiang, Xiao-Min Hu, Bi-Heng Liu, Chuan-Feng Li, Guang-Can Guo, René Schwonnek

(This is not directly quantum cryptography, but more generally quantum information theory. However, this is the category where it fits best.)
Here, we report on an experimental implementation of uncertainty-based entanglement witnesses, benchmarked in a regime dominated by strong local noise.

Journal: Physical Review Letters 122, 220401 (2019)
ArXiv: 1810.05588