Abstract: The method is for dynamically authenticating and authorizing a user. A request signal (104) is received from a user into a service unit (97). The service unit extracts identification information (101) from the request signal. The service unit evaluates the identification information and identifies potential users (X, Y, Z). The service unit assigns a probability value (Px, Py, Pz) to each identified potential user (X, Y, Z) to indicate a likelihood of correct identification of the potential users (X, Y, Z). The service unit provides rules sets (RSx, RSy, RSz) for the users (X, Y, Z). The probability requirements (PrRx, PrRy, PrRz) of each rule in the rules sets (RSx, RSy, RSz) are evaluated. The rules are applied for each (PrRx, PrRy, PrRz) less than or equal to (Px, Py, Pz).