Fundamental Finite Key Limits for One-Way Information Reconciliation in Quantum Key Distribution

Understand

The security of quantum key distribution protocols is guaranteed by the laws of quantum mechanics.

• However, a precise analysis of the security properties requires tools from both classical cryptography and information theory.
• Here, we employ recent results in non-asymptotic classical information theory to show that one-way information reconciliation imposes fundamental limitations on the amount of secret key that can be extracted in the finite key regime.
• In particular, we find that an often used approximation for the information leakage during information reconciliation is not generally valid.