Security analysis and improvements of XOR arbitrated quantum signature-based GHZ state

Abstract

Recently, Zheng et al. presented a novel signature protocol with arbitrator based on XOR encryption and GHZ state. Unfortunately, their protocol lacks security. Firstly, a quantum adversary can forge their signature based on the received information. On the other hand, their protocol is vulnerable for the adversary’s repudiation attack. Then, we bring about improvements on its security, efficiency and practicality. The improved protocol not only prevents the security defects of the old protocol, but also has better computation efficiency. On the other hand, our protocol is mainly used to sign the classical messages, which are widely used in the current network.