Reducing Quantum Errors and Improving Large Scale Quantum Cryptography

TL;DR

This paper proposes a quantum coding scheme that significantly reduces errors in quantum cryptography, enabling long-distance secure communication and robust quantum privacy amplification.

Contribution

It introduces a novel quantum error reduction method using N=q^2 qubits to encode a single qubit, enhancing quantum cryptography capabilities.

Findings

Error decreases exponentially with n

Enables long-distance quantum key distribution

Provides new quantum privacy amplification techniques

Abstract

Noise causes severe difficulties in implementing quantum computing and quantum cryptography. Several schemes have been suggested to reduce this problem, mainly focusing on quantum computation. Motivated by quantum cryptography, we suggest a coding which uses $N$ quantum bits ($N=n^2$) to encode one quantum bit, and reduces the error exponentially with $n$. Our result suggests the possibility of distributing a secure key over very long distances, and maintaining quantum states for very long times. It also provides a new quantum privacy amplification against a strong adversary.