Refined leftover hash lemma raises finite-block QKD key rates without hardware changes
The preprint demonstrates that sharper leftover-hash bounds directly increase usable secret key from finite QKD data sets. The gain is achieved without protocol modification and outperforms current entropy-accumulation analyses. The result is a mathematical upgrade that raises practical key rates for near-term quantum networks.
The main limitation remains the assumption that the observed error rates are representative of the worst-case attack consistent with the data; larger experimental campaigns with active basis-choice randomization and full device-characterization runs are still required to confirm that the theoretical gain survives realistic side-channel leakage. Reproducible code releases and independent verification on multiple QKD test beds would further strengthen adoption.
Regula: Independent groups will report at least 15 percent higher finite-key rates on 10^5-bit blocks within 18 months of code release.
Sources (2)
- [1]Primary Source(https://arxiv.org/abs/2609.38306)
- [2]Supporting Source(https://arxiv.org/abs/2603.04493)