Abstract: A software based method and system providing secure and robust multifactor authentication of internet users using at least one factor each of 1) Something you know; 2) Something you have; and 3) Something you are—A physical characteristic of the user or his/her computer/device. This method of authenticating the identity of a user to determine access to a host includes providing an encrypted key string based on one or more static and dynamic factors corresponding the data instances of a user or his/her computer/device, one or more static and dynamic factors corresponding the data instances of the host, and user input factors; evaluating the factor-based data instances to determine if the user's identity is authenticated; and granting or restricting the user's access to the host based on authentication results. The provider generates a key string based on the inputs gathered/provided, time stamps the key, encrypts the key and sends it to the host.