Semi-quantum bi-signature scheme based on Bell states

Currently, quantum signature protocols assume that all participants in the protocol (signers, verifiers, and arbitrators) should exhibit quantum capabilities. If quantum devices are lacking, the quantum signature protocol cannot be implemented. However, quantum devices are not widely used, and not all users can own quantum devices. Boyer et al. first proposed the concept of the semi-quantum environment. Zhao et al. proposed a semi-quantum signature protocol with double signers based on the W state. Yang et al. discovered that in the semi-quantum signature protocol with double signers developed by Zhao et al., an internal attacker could launch an impersonation attack during the verification and signature stages to capture the private key and use it to impersonate the user’s identity. In addition, the eavesdropper can obtain all the secret information of the signers by performing a man-in-the-middle attack. All three attack modes can pass the eavesdropping check. Hence, if these security problems are not solved, the signature of the semi-quantum signature protocol with double signers proposed by Zhao et al. cannot be completed safely. Therefore, based on Bell states, a new semi-quantum signature protocol of double signers was developed in this study. The proposed protocol not only resists impersonation attacks and man-in-the-middle attacks but also resists other common attack modes.