Security for controlled access systems

摘要

In order to gain access to a secured system, a user must be able to enter valid user identification information and must also have a remote wireless communication device such as a pager or cellular telephone having a number that is substantially unique to that user. When the user requests access to the secured system, the system places a call to the user's remote wireless communication device and sends that device revalidation information such as a random number generated by the secured system. The user must return the revalidation information to the secured system to gain access. In an alternative embodiment, another person (a user-approver) has the remote wireless communication device and must return the revalidation information to the secured system if the user-approver approves the user's request for access.