Security and Privacy Security issues are critically important in any digital-payment mechanism. The most common way to authenticate a user is to ask for a password. Because it's easy to read messages as they traverse the Internet, most commercial services encrypt passwords before sending them, using the new generation of WWW browsers. Unfortunately, even encrypted passwords aren't secure if they are used more than once. Current cryptographic mechanisms can provide these features.
Privacy is a related but more controversial issue.
In this age of mammoth databanks, many people think that it's time to draw the line. This goal can be achieved with existing digital cryptographic technologies, but only some electronic-payment systems currently make use of them. Neither is due to be available until late this year, and neither is well defined at present. But the six services examined here are close enough to real-world deployment that a realistic evaluation of their implementations and prospects is possible. Thus, customers will talk to the bank, not to Cybercash, for customer service.