1. A computer, comprising: a virtual system platform; a first guest operating system installed on the virtual system platform, for installing a service application module, wherein the service application module generates a security information input interface when it is being executed; and a second guest operating system installed on the virtual system platform; characterized in that the second guest operating system comprises: a dynamic password generation module for generating security information, the security information is input into the security information input interface and is sent to a network server for authentication.