Security of Post-selection based Continuous Variable Quantum Key Distribution against Arbitrary Attacks

TL;DR

This paper extends the security proof for post-selection based continuous variable quantum key distribution, demonstrating security against arbitrary attacks using an equivalent protocol approach and providing explicit performance evaluation for noisy Gaussian channels.

Contribution

It introduces a method to prove security against arbitrary attacks by modeling post-selection as a projective measurement, enabling practical security calculations.

Findings

Security can be assessed using experimentally accessible quantities.

Explicit performance evaluation for noisy Gaussian channels.

Security proof applicable to arbitrary eavesdropping attacks.

Abstract

We extend the security proof for continuous variable quantum key distribution protocols using post selection to account for arbitrary eavesdropping attacks by employing the concept of an equiv- alent protocol where the post-selection is implemented as a projective quantum measurement. We demonstrate that the security can be calculated using only experimentally accessible quantities and finally explicitly evaluate the performance for the case of a noisy Gaussian channel in the limit of unbounded key length.