Measurement-Device-Independent Semi-Quantum Digital Signature for Multi-Classical-Users

We design a measurement-device-independent semi-quantum digital signature (MDI-SQDS) protocol that enables communication between multiple classical users. Our protocol benefits from the fact that the MDI component can remain secure when the measurement device is under the control of an eavesdropper. In addition, our protocol enables the classical participants with low technical capacity to enjoy the advantages of quantum cryptography in practice. Moreover, optical delay devices play an important role in enhancing the security of communication by encrypting information. Furthermore, based on security analysis, our protocol is robust against denial and forgery attacks.