The concept of electronic money is no longer a hypothesis but a realisation. Advanced smart card technology and the ability to replace physical cash with an electronic alternative is a reality with mass market utilisation being a matter of time, rather than just supposition. Mondex is an “electronic cash” smartcard, which is being introduced as an alternative to physical notes and coins for use in the high street and as a future payment mechanism in a wide variety of areas such as the Internet and multimedia services. It is also the pre-eminent product of its kind for it fully re-combines the existing features of physical money with additional utility; and it has been this type of behaviour which improves an existing paradigm that has advanced payment systems over the ages. Fundamental to any system will be its reliance on security, thereby imposing confidence among its scheme participants and ensuring the scheme’s success. The Mondex chip is virtually impossible—and almost certainly uneconomic—to crack. Therefore, within the features of Mondex—improved flexibility, acceptance, convenience, control, etc.—there exists the assets of security, scaleability and economy. In addition, the Mondex proposition will provide a foundation upon which entirely new business, social and economical activity could occur.