You probably know people who are reluctant to buy goods on line, even from brand-name companies such as Amazon and eBay, or the Web sites of Old Navy, Target, or Nike. In a way, they're right to be suspicious. If your browser uses today's standard of 128-bit encryption, the information you send to any secure site goes out from your computer encrypted. This data could be unencrypted with a lot of effort, but probably is not breakable in a reasonable amount of time, except perhaps by the National Security Agency (and the NSA, so far as we know, has not shown any interest in stealing credit card numbers of American citizens or trying to find out who is ordering sexy videotapes or kinky underwear).