Abstract: A system that uses inferencing to deal with complex authentication problems such as those that occur when users authenticate themselves by means of tokens. A troubleshooter responds to a user's request for help by inputting an identification code for the user's token into the system. The system uses the identification code to obtain the current authentication state for the token from an authentication database and then inputs the authentication state to an inferencing system such as a knowledge base. The inferencing system uses the authentication state to make inferences concerning the problem. The inferencing process may involve obtaining further information from the troubleshooter an/or the authentication database and may also provide warnings of particular security problems to the troubleshooter. Eventually, the inferencing system reaches a solution, which may include advice that the troubleshooter is to give to the user.