Gernot Alber

Lukas Fladung, Georgios M. Nikolopoulos, Gernot Alber et al.

Optical physical unclonable keys are currently considered to be rather promising candidates for the development of entity authentication protocols, which offer security against both classical and quantum adversaries. In this work we investigate the robustness of a continuous-variable protocol, which relies on the scattering of coherent states of light from the key, against three different types of intercept-resend emulation attacks. The performance of the protocol is analysed for a broad range of physical parameters, and our results are compared to existing security bounds.

Matthias Geihs, Oleg Nikiforov, Denise Demirel et al.

Sensitive digital data, such as health information or governmental archives, are often stored for decades or centuries. The processing of such data calls for long-term security. Secure channels on the Internet require robust key establishment methods. Currently used key distribution protocols are either vulnerable to future attacks based on Shor's algorithm, or vulnerable in principle due to their reliance on computational problems. Quantum-based key distribution protocols are information-theoretically secure and offer long-term security. However, significant obstacles to their real-world use remain. This paper, which results from a multidisciplinary project involving computer scientists and physicists, systematizes knowledge about obstacles to and strategies for the realization of long-term secure Internet communication from quantum-based key distribution. We discuss performance and security particulars, consider the specific challenges arising from multi-user network settings, and identify key challenges for actual deployment.