Security analysis and improvement of an arbitrated quantum signature scheme

Abstract We analyze the security of Jiang et al.’s arbitrated quantum signature scheme based on local indistinguishability of orthogonal product states. First, Jiang et al.’s scheme cannot resist against the forgery attack. Second, it is insecure against disavowal attack. Then, an improved arbitrated quantum signature scheme is proposed. The new scheme overcomes the security drawbacks of Jiang et al.’s scheme and it is secure against forgery attack and disavowal attack. What is more, it is more efficient than the old scheme. On the other hand, our quantum signature scheme is based on product states, which can be obtained straightforwardly, thus our scheme is easier to implement than the schemes using cluster states.