Using baseline profiles in adaptive authentication

An improved technique of processing an authentication request from an authentication requestor involves an adaptive authentication device comparing a behavioral history of fact values associated with a user over a current time window with a user's baseline profile that includes a behavioral history of the fact values. The adaptive authentication device accesses such a behavioral history over several previous time windows from a database whose entries include a user identifier, a time interval and user data which represents fact value behavioral history over the time interval. When the device receives an authentication request from an authentication requestor, the adaptive authentication device matches a username of the request with a user identifier of an entry of the database whose time period is the current time period. The adaptive authentication device then updates fact values representing the user's current behavioral history and compares the current behavioral history to the user's baseline profile.