Internet Security is increasingly of concern as more and more cases of identity theft of online data is reported. Simple login and password authentication for access to sensitive websites like financial, health or other personal data is no longer sufficient. Several mechanisms for additional security, called two-factor authentication have been proposed. Most of them involve the use of a physical device like a card which is read by a card reader or suggest the use of biometric authentication. Although, these are very secure, the cost of implementation of these "physical" authentications is high. This invention outlines the use of a simple two factor authentication using mobile phones, PDAs or Credit and Debit cards that most users already have, without the need for any special hardware.