Security proof for a simplified BB84-like QKD protocol

TL;DR

This paper proves the security of a simplified BB84-like quantum key distribution protocol in finite-key scenarios, demonstrating it remains secure with fewer measurement operators, enabling resource-efficient implementations.

Contribution

It provides a security proof for a resource-efficient, simplified BB84-like QKD protocol with fewer measurement operators in finite-key settings.

Findings

Security maintained with fewer measurement operators

Finite-key security proof established

Resource-efficient time-bin encoding scheme enabled

Abstract

The security of quantum key distribution (QKD) has been proven for different protocols, in particular for the BB84 protocol. It has been shown that this scheme is robust against eventual imperfections in the state preparation, and sending only three different states delivers the same secret key rate achievable with four states. In this work, we prove, in a finite-key scenario, that the security of this protocol can be maintained even with less measurement operators on the receiver. This allows us to implement a time-bin encoding scheme with a minimum amount of resources.