Security authentication method and system

The invention discloses a security authentication method and system, when a unique hardware identification number of an external security authentication device is authenticated, a user needs to select a user name and a service type on the security authentication device and input a security password, and when the security authentication device passes the authentication of the security password input by the user, the user needs to select the user name and the service type on the security authentication device. And sending a confirmation signal to the computer, and after the computer receives the confirmation signal and verifies that the confirmation signal is legal, unlocking the selected service. According to the method, the existing network equipment such as a mobile phone, a personal mobile computer and the like can be fully utilized, so that the cost increase caused by reconfiguring the external security authentication equipment is avoided, and the use security of the computer and the network is ensured. Ac