Introduction

With the modern world becoming more and more computerized every day, such things as face-to-face conversations and paper mail are becoming remnants of the past. Why walk to the other end of the building to ask a question when you can send an instant message or an e-mail? Why pay a long-distance fee to talk to people around the world when you can use the Internet or even the company s local intranet for virtually nothing? With each new emerging technology, our lives are made easier as we put greater trust in computers.

Unfortunately, a problem has arisen in many organizational environments; this problem differs from problems encountered in the home. The problem involves security. Would you send a piece of paper mail with no envelope? Would you conduct private financial transactions on a postcard? Of course not. So why would you send an insecure piece of electronic mail? When an electronic message (which could be e-mail or any other application s data that flows over a network) is sent unsecured, it is available for anyone with the necessary knowledge and equipment to see. As part of the effort to solve these problems, many products and technologies have been developed that enhance the security of messages by digitally signing and encrypting them. One of the most popular of these technologies is public/private key technology, which requires that each user have a private key that only that user possesses and for which only that user knows the password. A smart card