Electronic Commerce Initially, the Internet was designed for use by government and academic users, but it is now rapidly becoming commercialized. It has online "stores" and even electronic "malls". Customers, browsing on their computers, can view the products, read the descriptions and sometimes even try the samples. What they lack is the ability to buy from the keyboard, on impulse. They could pay by credit card, transmitting the necessary data via modem; but intercepting messages on the Internet is trivially easy for a smart hacker, so sending a credit card number in an unencrypted message is a risk of trouble. It would be relatively safe to send a credit card number encrypted with a hard-to-crack code. This would require the general adoption of standard encryption protocols on the Internet or the conclusion of prior agreements between buyers and sellers. Both consumers and merchants could see a windfall if these issues are resolved. For merchants, a secure and easily divisible supply of electronic money will motivate more Internet surfers to become online shoppers. E-money will also make it easier for small businesses to achieve a level of automation already enjoyed by many large corporations, whose legacy of electronic data exchange means that streams of electronic bits now flow instead of cash into back-end financial processes. We must resolve four key technological issues before consumers and merchants give electric money the same real and perceived values ​​as our tangible notes and coins. These four key areas are: security, authentication, anonymity and divisibility. Commercial research and development departments and university laboratories are developing measures to address security for both transactions over the Internet and on private networks. The venerable answer to protecting sensitive information, like credit card numbers, is to encrypt the data before sending it. MIT's Kerberos, named after the three-headed guard dog from Greek mythology, is one of the best-known private key encryption technologies. It creates an encrypted data packet, called a ticket, that securely identifies the user. To make a purchase, you generate the ticket during a series of coded messages that you exchange with a Kerberos server, which sits between your computer system and the one you're communicating with. The latter two systems share a secret key with the Kerberos server to protect information from prying eyes and to ensure that your data is not altered during transmission. But this technology has a potentially weak link: if the server is hacked, the watchdog rolls over and plays dead.