Phishing scams cost Americans nearly $1 billion during the last year, a research firm said in a recently-released survey.

According to a poll of 5,000 U.S. Internet users that Gartner conducted in May, phishing attacks are not only up -- despite what some industry analysts have said -- but they're continuing to grow by leaps and bounds.

"A lot of people -- analysts mostly -- thought that phishing was just a bunch of noise in the system, and that after 2004, it would slow down," said Avivah Litan, a research director with Gartner. "That hasn't happened."

Instead, during the 12 months that ended in May 2005, 73 million American adults who use the Internet said that they "definitely" received or "thought they received" an average of more than 50 phishing e-mails. That number, said Litan, was 28 percent higher than the previous year, when 57 Americans reported that they'd been the target of phishing scams.

More telling, Litan went on, was what she's been hearing from Internet service providers, who are reporting a four-fold increase in the volume of phishing e-mails in just the last six months. (And that excludes what Litan estimated as the 30 percent of attacks which go unreported.)

"What surprised me was what the ISPs are saying," Litan said. "I knew it was bad, but I didn't know it was this bad."

Obviously, present anti-phishing methods aren't working. "If they were, these attacks wouldn't be getting through."

Only America Online is actually identifying and blocking phishing mail from reaching its members' mailboxes, Litan said. But even if others follow suit, that won't eliminate the problem. "That would help stop theft at what I call the server level," said Litan. "But if that happens, phishers will just step up their efforts to fly under the radar."

Most analysts, Litan included, have noted for months that phishers are getting sneakier, with tactics that include planting keyloggers which watch for specific URL log-in usernames and passwords (to hijack access to online bank accounts, for example).

Litan's numbers also reveal massive losses by consumers and their banks. By extrapolating the survey results, she estimated that 1.2 million U.S. adults lost money because of a phishing attack in the past 12 months. The total dollar impact: $929 million.

Nor is consumer awareness or education about phishing affecting the bottom line. Although a smaller percentage of phishing e-mail recipients actually clicked on a link embedded in the message -- 15 percent this year compared to 19 percent the year before -- the rate at which people fell for the scam hook, line, and sinker dropped just a half percentage point, from 3 to 2.5 percent.

What people want to combat phishing, but what they're unlikely to soon get, said Litan, is two-way authentication on the Web, where a Web site authenticates itself to the consumer as being legitimate. (Currently, Internet authentication schemes only validate the consumer to the site.)

"We really need two-way authentication, but that's really dependent on the browser, and no one seems interested in following through," said Litan.

She's not optimistic about the future. "Nothing's been done in the last year about phishing. It's actually gotten worse. A whole year after it first got attention and everyone said we had to get to work on the problem, here we are."