Abstract:  In traditional identity authentication schemes， methods such as passwords， tokens and biometric features often require users to authenticate themselves while having an electromagnetic connection with the server. These pose security risks of authentication information being intercepted and attacked. Therefore， the article designs an identity authentication scheme based on national cryptographic algorithm in no connection. Through the coordination of QR codes and national cryptographic algorithm， the scheme forms a complete closed-loop process to verify the user’s identity in the state of no connection between the authenticator and the user. Compared with traditional identity authentication schemes， the connectionless authentication scheme proposed in this paper can effectively avoid the danger of potential electromagnetic attacks. The scheme has the characteristics of simple principle， higher security and less investment， which is practiceable in non-contact access control， information system login verification and other scenarios.

Key words: no connection, identity authentication, national cryptographic algorithm, QR codes, avoiding electromagnetic attack