Smart cards are now the most prevalent computer in the world. In particular, they are the central piece of the wireless revolution. The brain of 600 million mobile phones, they bring personal, secure computing to the world population in the most egalitarian spread of advanced technology.

Since the birth of the era of open smart card systems a little more than five years ago, the speed and memory of smart cards have multiplied ten-fold. The sophistication of both smart cards and their environment, their maturity in terms of concepts and applications, called for a book attempting to map the new technological landscape.

It is my pleasure to introduce a book written by two of the top experts in the world in smart card technology. Active in smart card standardization bodies, practitioners of smart card technology, actual participants in key projects, Scott and Tim have the perspective and knowledge needed to convey to a wide audience the fundamentals of smart card developments.

Smart cards are in the heart of our cell phone, in our wallet to secure your financial transaction, pinned on our clothes as a corporate badge, and we use them too as tickets for public transportation. Each time, they are our own, trusted, electronic representation, giving us keys to services that are fundamental for our interaction with the environment.

Scott and Tim have taken the challenge of explaining how this is all made possible. Each of us in the smart card business remembers our first months in the field, borne out of confusion, awe, and sometimes desperation; looking at the complexity of smart card systems. This book tries to peel each layer of complexity out of the smart card world.

The basic smart card concepts are grounded on interoperability, brought by an extremely rich web of standards covering everything from physical appearance to arcane details of software interactions. The book not only presents established practices, it also tries to convey in a very effective way today's hot debates and their implication for the future of the technology.

Once the basics are mastered, the challenge is to assemble the knowledge acquired, into systems assembling the chain of trust needed to securely build smart card systems. By going in detail into the description of card infrastructure software, the authors help the reader understand how smart cards are the cornerstone of computer security.

The tools can then be played out for building applications in the critical domains of smart card deployment: mobile telephony, financial exchanges, information technology, digital rights, and transport. Thanks to very specific examples, readers should be able to translate the book's illustrations into applications related to their own business and specialty.

Finally, no technical panorama would be complete without an attempt to look beyond the horizon. I appreciate that Scott and Tim wandered into the unknown and, if they may not show us the future, they show us very candidly how experts in the field think about the future.

I now let you enjoy the book. Once you've passed the maelstrom of new concepts and techniques, I hope that you will participate in the smart card adventure where these ubiquitous, secure, and cheap computers are core components of the information infrastructure at the beginning of the 21st century.