I have gone under cover.

After surfing the Web as Leslie Walker for almost five years, nobody recognizes me online now, except when I choose to show my real digital face. Often I appear as "songstress@freedom.net" or "antiquedealer@freedom.net," even when I am sending e-mail from my personal account at Erols.com.

I am testing a month-old privacy tool called Freedom. It cloaks my identity in a pseudonym and encrypts any data that I send multiple times before dispatching it through cyberspace.

Freedom drops a veil of secrecy not only over my e-mail but also over all the electronic trails (including those small text files called "cookies") left by my Web browser, any live chat I do on Internet Relay Chat and messages I post to Internet discussion groups.

This tool is not for the digitally faint of heart--at least not yet--for it costs $49.95, takes about an hour to install and can slow down your Web surfing experience. But I do believe Freedom bears watching because it is moving to the front lines of a crucial Internet battle--the one for control of consumers' personal profiles.

As its Montreal-based maker rolls out a strategy for wider distribution over the next several months, it will test how much privacy consumers are willing to sacrifice for the highly touted conveniences of electronic commerce. The implications are significant for both consumers and merchants, as well as law enforcement agencies and governments around the world. If it catches on, the software could threaten the financial underpinnings of the Internet's emerging advertising networks.

For the first time, people can choose to go incognito as they travel the Web simply by pointing and clicking at tiny pictures of aliases they create called "nyms." Not even Zero-Knowledge Systems Inc., the creator of the software, will know who they are--and couldn't figure it out even if the FBI swooped in with a dozen court orders. That is because unlike most anonymizers, which store people's true identities in a central database, Zero-Knowledge uses a double-blind system of electronic "tokens" to create pseudonyms and stores the digital keys on each consumer's computer. Only consumers have access to their keys.

The potential to hide hackers, thieves and teen-porn peddlers online has caught the attention of law enforcement agencies. Zero-Knowledge has met with the Royal Canadian Mounted Police and the U.S. Department of Justice; it plans more meetings soon with the FBI, CIA and Secret Service.

But the company's president, Austin Hill, maintains that the software will help more than it hurts society because it contains a digital authentication system that also lets people prove their real identities.

Overseas, the software could wreak havoc on governments trying to monitor what their citizens say and do online. A Chinese dissident using Freedom could be as invisible and free of governmental censorship on the Internet as an American.

The commercial implications are equally potent. Using Freedom, consumers wouldn't have to surrender their entire Web surfing history to online marketers anymore. Now the question becomes: How much do we really care about our privacy? Enough to go out of our way--even spend money--to avoid spilling our digital guts to every online merchant we see?

That is what most of us are doing, even though we may feel hidden behind surfs4fun@hotmail.com. Our e-mail is no more secret than a printed postcard as it hops along the Internet. Our digital tracks are traceable to our real-world selves. And big Web advertising networks such as DoubleClick Inc. are compiling profiles of our Web-browsing habits and storing them in their giant databases.

Still, most people likely will find it too much trouble to fool around with software that finished its "beta" testing barely four weeks ago. Even those willing to take the time to download the software from the Freedom.net Web site for the free 30-day trial may find traveling online maddeningly slow, partly because the system encrypts and reroutes data through a private network of servers.

But I believe that will change. I found Freedom surprisingly easy to use after getting over the installation hassle. Performance should improve as Zero-Knowledge adds more servers and signs deals to place them strategically along the Internet's backbones. Eventually using a tool like this likely will pay consumers more than it costs because it should allow them to trade information about themselves to merchants in exchange for cash or price discounts.

Privately held Zero-Knowledge, which employs about 150 people and hopes to have 300 soon, is signing deals with partners (think about online personals, gay chat rooms, health-care advisers) who want to distribute private versions to their privacy-craving customers. While it isn't going to work with America Online any time soon, versions are on the way for Macintosh computers and operating systems such as Linux and Microsoft NT.

Scores of programmers are working on the next software version in an attempt to make it easier to use and more powerful. Zero-Knowledge plans to create more sophisticated nyms with special tools for managing bonus-point rewards programs online, for designating favored merchants and accepting e-mail marketing offers from them, and for controlling what kind of personal information each nym releases when goods and services are purchased. Eventually, it hopes to offer automated agents to negotiate with merchants on behalf of each nym.

"This is the next major milestone in the way the Internet works," said Hill. "When you give end users control over the amount of data they release about themselves online, then you have a 'me' economy where everything is based on me."

I believe the perfect e-nonymizer still eludes Internet entrepreneurs, though many undoubtedly are trying to build it. It will totally divorce you from your credit card, allowing you buy online without identifying yourself to any merchant. It should be like cash in the real world--you give it to a merchant, who usually has no idea who you are, and you take away your goods. Hill won't reveal details but acknowledges his company is pursuing that goal.

Currently, when you want to buy anything using Freedom, the nyms can't conceal your identity because you must reveal the name on your credit card and shipping address to take delivery. I expect that to change eventually. In the meantime, Zero-Knowledge suggests you create one nym with your real name to make the transition from anonymous Web surfing to purchasing under your true identity quick and easy.

Hill and his co-founders (his father and brother) realize they are putting their money squarely on the other side of where big business is placing its bet on the Internet: advertising targeted to highly personal profiles. The Hills believe consumers won't want anyone tracking them for free after they discover controls that will allow them to negotiate directly with merchants.

"I think profile-based marketing will go away as an Internet business model," Hill said. "It's a dead industry. They just don't know it yet."

CAPTION: The Freedom software puts a control panel on the desktop, allowing users to select which pseudonym they want to use from a pull-down menu. Users can create different "nyms" for different interests or activities--chatting, shopping, e-mail--and decide how much information about themselves to disclose with each.