Tight finite-key analysis for generalized high-dimensional quantum key distribution

Due to the capability of tolerating high error rate and generating more key bits per trial, high-dimensional quantum key distribution attracts wide interest. Despite great progresses in high-dimensional quantum key distribution, there are still some gaps between theory and experiment. One of these is that the security of the secret key heavily depends on the number of the emitted signals. So far, the existing security proofs are only suitable in the case with an infinite or unpractically large number of emitted signals. Here, by introducing the idea of key classification and developing relevant techniques based on the uncertainty relation for smooth entropies, we propose a tight finite-key analysis suitable for generalized high-dimensional quantum key distribution protocols. Benefitting from our theory, high-dimensional quantum key distribution protocols with finite resources become experimentally feasible.

Automated summary

High-dimensional quantum key distribution has advantages in tolerating high error rates and generating more key bits per trial, but there remain gaps between theory and experiment, especially in the relationship between key security and the number of emitted signals. By introducing key classification and relevant techniques based on the uncertainty relation for smooth entropies, a tight finite-key analysis for generalized high-dimensional quantum key distribution protocols is proposed, making it experimentally feasible with finite resources.