Quantum Key Distribution With several intercept-resend attacks Via A Depolarizing Channel

TL;DR

This paper analyzes how depolarizing channels affect the security of the BB84 quantum key distribution protocol under multiple intercept-resend attacks, by calculating error rates and mutual information.

Contribution

It provides a detailed study of the impact of depolarizing noise on QKD security with multiple eavesdroppers, including analytical expressions for error rates and information.

Findings

Depolarizing channels increase quantum bit error rates under attack.

Mutual information decreases with more intercept-resend attacks.

Security thresholds depend on the level of depolarization.

Abstract

The disturbance effect of a depolarizing channel on the security of the quantum key distribution of the four state BB84 protocol with multiple sequentiel intercept and resend attacks of many eavesdroppers, has been studied. The quantum bit error rate and the mutual information are computed for arbitray number of attacks.