Not too long ago, a hacker broke through a "secure" Internet vendor's system, getting at thousands of credit card numbers. The news media, as it tends to do, had a field day; and while the reaction -- knee-jerk, anti-Internet, pedestrian -- was histrionic, the incident begs the question: Is it safe to give out your credit card number online? there a difference between giving your number out online and to someone on the phone? Or to that smirking waiter? No -- except that an online vendor may have a database of many people’s credit card numbers, and that's what whets hackers' appetites: volume. That's why, as merchants, banks and software companies scramble to find ways to get you to spend -- presenting such options as digital cash and digital credit cards -- there is a lot of talk about encryption and digital identification. Pretty Good Privacy is a leader in digital-privacy software; its page discusses what those buzz-words mean. To explain briefly, e-cash and e-credit are similar concepts -- they require you to set up an account with an e-cash provider and buy only from merchants who also have registered with that provider. When you purchase something online, it gets charged to your real credit card, with the providers taking extra measures to protect your security. They come in different flavors. For free, CyberCash software encrypts your credit card information as it travels from your computer across the Web, protecting it with industrial-strength code. Once registered, you're issued a password and, voilà!, your virtual wallet is loaded with plastic. When you go to purchase an item online, CyberCash confirms your identity via a password, then contacts your bank, meaning the merchant never receives your credit card number. The catch? You can shop only at the merchants that are CyberCash-enabled. First Virtual takes security measures a step further, by holding onto your credit card information and acting as intermediary when you buy online, keeping your credit card number out of cyberspace and, probably, out of danger from thieves. Register your credit card number with First Virtual over the phone to receive a "VirtualPIN" number. When you buy something online at a participating merchant, that business receives your identification number, not your credit card number. The merchant, in turn, verifies your identification number with First Virtual. The advantages to this service are that it doesn't require any special software and it sidesteps the issue of sending your credit card number online. The downside: Once again, you can shop only at sites that accept this service. Although electronic -- or digital -- cash is not yet widespread, banks are issuing it, allowing you to purchase items at registered retail sites. Electronic credit cards are coming up fast, employing coded messages, secret numbers and electronic buyer identification. VeriSign is another company specializing in Internet safety; it has a page that discusses digital identification. Another guarantee of security can be found in Secure Electronic Transaction, a technical specification for securing payment card transactions over open networks, such as the Internet. SET was developed by Visa and MasterCard, with participation from several technology companies, including Microsoft and IBM. This system means that your entire credit card number is never traveling across the ‘Net -- rather, pieces of it are -- and that no human eyes see your entire card number. WEBsmith has a page explaining what this means to the consumer with e-commerce news and definitions of the relevant terms. Also helpful is How the 'Net Changes Business. This page was put together by a group of students at The University of Texas at Austin for an Internet class, and it thoughtfully examines how businesses get on the 'Net, how they are making their presence known, what shopping on the 'Net is like and how safe it is.