# Quantum Key Distribution with no Shared Reference Frame

## TL;DR

This paper demonstrates that quantum key distribution can be successfully performed without any shared reference frame between communicating parties, broadening the practical applicability of quantum communication.

## Contribution

It introduces a method for QKD that does not require any shared reference frame, extending the feasibility of quantum communication in more general scenarios.

## Key findings

- QKD is possible without a shared coordinate system
- The method generalizes to other transformation groups
- Practical quantum communication becomes more flexible

## Abstract

Any quantum communication task requires a common reference frame (i.e. phase, coordinate system). In particular, Quantum Key Distribution requires different bases for preparation and measurements of states which are obviously based on the existence of a common frame of reference. Here we show how QKD can be achieved in the absence of any common frame of reference. We study the coordinate reference frame, where the two parties do not even share a single direction, but the method can be generalized to other general frames of reference, pertaining to other groups of transformations.