| 摘要 |
A network security system controls access to a resource. A client station provides for inputting an access request for access to a resource via a network, for example the Internet. The access request identifies the user and the resource to be accessed. A server holds data regarding users including a contact address for a communications device of the user and is responsive to the access request to issue an authentication request to the communications device. A communications device includes a receiver for receiving the authentication request from the network resource, a controller operable to invite a user to input a response to the authentication request and a transmitter to return the response to the server. The server is further operable to evaluate a received response for determining whether the user is permitted to gain access to the resource. Authentication of requests for access to resources via a network is provided in a flexible manner using readily available components in a flexible manner, for example a mobile telephone. |
