4.2.1 Introduction

With the explosion of interest in the World-Wide Web, hundreds, if not thousands, of companies have rushed to get their home pages online to provide general information, advertise, and offer catalogs. Many of them would like to accept orders from customers online.

However, these firms generally have found the level of security in Internet applications woefully inadequate. Companies want tools that allow them to know with some certainty that customers are who they claim to be so that billing can be charged against the proper accounts.

Similarly, consumers are concerned about security and privacy of online transactions. They want to know that personal account information or credit-card numbers will be seen only by authorized eyes. And as vendors want to verify that a credit-card number is indeed a customer `s, consumers want assurance that a person who purports to represent an online service really belongs to that service.