Patent US 5,774,525

A method and corresponding apparatus utilizes questioning to provide secure access control including the steps of storing information in a database; generating at least one question based upon the information stored in the data base; communicating to the user the generated question(s); receiving a response associated with the question(s), interpreting the response to determine whether the response conforms to the information upon which is based the associated question(s); and outputting an authorization status indicating whether or not the user is authorized for access according to the determination. The question(s) concerns a relationship among portions of information contained in said data base. This feature is advantageous because it protects against an eavesdropper gaining access to the service or facility and provides the capability of generating a relatively large number of different questions from a small data base. Furthermore, the questions asked of the user may be based on dynamic data, which advantageously protects against eavesdroppers gaining access to the service or facility. In addition, the number and/or type of questions generated by the first module may correspond to a security level of the system. The security level may be set by the service or facility, or may be set the system control module according to user input.