A firewall for authenticating a user access request is disclosed. The firewall device may include a proxy process for processing incoming connection requests. The proxy is configured to receive an access request from a user over a first communication medium and prompt the user for a username and a first password portion over the first communication medium. The firewall may then send a second password portion to the user over a communication medium other than said first communication medium responsive to receiving a valid user name and first password portion pair from the user. The firewall may then verify the access request responsive to receiving the second password portion from the user through the first communication medium. The firewall may send passwords to a mobile device for verification.