Quantum digital signatures with smaller public keys

TL;DR

This paper proposes a quantum signature scheme using nonbinary symbols and multiple partial key revelations, reducing qubit usage per message bit while maintaining security.

Contribution

It introduces a novel quantum signature method with smaller public keys by allowing multiple partial private key disclosures.

Findings

Reduces qubits needed per message bit

Provides a security proof for the scheme

Shows numerical results on public key size improvements

Abstract

We introduce a variant of quantum signatures in which nonbinary symbols are signed instead of bits. The public keys are fingerprinting states, just as in the scheme of Gottesman and Chuang, but we allow for multiple ways to reveal the private key partially. The effect of this modification is a reduction of the number of qubits expended per message bit. We give a security proof and we present numerical results that show how the improvement in public key size depends on the message length.