Improvement of a quantum broadcasting multiple blind signature scheme based on quantum teleportation

TL;DR

This paper critically analyzes a quantum broadcasting multiple blind signature scheme based on teleportation, revealing security flaws, and proposes an improved protocol that enhances security and reusability of secret keys.

Contribution

The paper identifies vulnerabilities in the existing scheme and introduces an improved protocol that resists attacks and allows key reuse, increasing practicality.

Findings

Original scheme allows message learning and modification by participants.

The scheme is vulnerable to participant and external attacks.

The improved protocol resists all identified attacks and supports key reuse.

Abstract

Recently, a broadcasting multiple blind signature scheme based on quantum teleportation has been proposed for the first time. It is claimed to have unconditional security and properties of quantum multiple signature and quantum blind signature. In this paper, we analyze the security of the protocol and show that the signatory Ui can learn the signed message m by a single particle measurement and the signed message m can be modified at random by anyone according to the scheme. Furthermore, there are some participant attacks and external attacks existing in the scheme. Finally we present an improved protocol and show that the improved scheme can resist all of the mentioned attacks. Meanwhile, the secret keys can be used again and again, which will make it more efficient and practical.