參考  What is SMB signing?

Server Message Block (SMB) signing is a security feature of Windows operating systems. SMB signing ensures that the transmission and reception of files across a network are not altered in any way. As the traditional SMB authentication is vulnerable to man-in-the-middle (MITM) attacks, the secure transmission of SMB traffic is required. Implementing mutual authentication SMB signing protects a network from these attacks. The SMB signing feature adds digital signatures into SMB packets to strengthen SMB authentication.