When you read what I write, do you know whether I exist? Do you know who I am? Do I know who I am?

Well, you know my name. You assume that I am a real person of that name, and that someone at this newspaper has contact with me. (In fact I file my column electronically, though I admit to have been seen on occasion!) Despite technological advances, people still start professional (or other) relationships after acquiring verifiable identification -- an address, a bank account, a face. What would happen in cyberspace, where people may be far apart geographically, and identities less rigid and secure?

Electronic identities as widely used, are limited to e-mail addresses. As with a physical address, an e-mail address provides a way to contact an individual. Like the postmark stamped on tree- murdering paper envelopes, e-mail headers generally indicate that a message has, indeed, come from a particular address and hence a particular person. Unfortunately these headers are easily forged. Not only can someone pretend to be me, I can pretend to be someone who doesn't exist!

Cybernauts see two issues here. The inherent insecurity of cyberspace, which makes normal interactions unreliable, is a lapse that demands attention. On the other hand, the amorphous nature of identity that the Net encourages is actually a Good Thing, balancing the ease with which privacy can be violated, and making the advantages of an information society apparent.

There are a number of ways to ensure distinct identities. That is, to ensure that Rishab Ghosh who writes this column is the author of the previous episode. Digital signatures are secure, backed by the arcane mathematics that proves the difficulty of factoring large numbers. A digital signature is a very large number, correlating the signed data with other publicly available numbers that define an individual's identity. Though these identifying numbers are public, a signature cannot be forged, as it also depends on a private key kept secret by the individual. Similar methods can be used by anyone to send encrypted messages that can be read only by the intended recipient.

There -- now I have an electronic identity. You might have noticed, though, that there is no link at all between an identity in cyberspace and any physical (real?) one. I could plausibly have multiple identities, for different purposes, conducting public arguments with each other. Which brings us to the Good Thing. There's no reason why I shouldn't write columns as Rishab Ghosh and poetry as Alfred Prufrock, while living the rest of my life as John Doe. I might have to, lest evil marketing managers monitor all my public actions and learn more about me than I do.

To formalize this separation of identities, cybernauts have created services known as anonymous remailers, which accept conventional e-mail and repost them, shorn of all their direct identifying marks -- addresses, names and so on. It is up to the poster to create pseudonymous identities using signatures and other methods. There are varying degrees of anonymity provided; with many services it is even possible to reply to anonymous mail without knowing a 'real' e-mail address.

This sort of anonymity might primarily be used for privacy -- from consumer surveys, cloak-and-dagger maniacs, and other assorted net pests. In an ideal world, we would be free to say what we like; till we are, anonymity allows us some freedom to express without reprisal. This freedom is already being taken advantage of; in Internet news groups such as alt.sexual.abuse.recovery, for instance, victims can comfort each other in public electronic gatherings without the risk of public exposure.

As with any technological advance, anonymity can be abused. While 'whistle blowing' might be the right thing to do sometimes, there is no way to be compensated for anonymous defamation. Attempts are being made towards a system of reputations, where people would gradually build (or ruin) a reputation for their identities, as their posts are tested by time. A totally anonymous accusation will of course have a very low reputation.

Reputation systems will not end identity abuse. Hopefully, as people depend on them to be taken seriously, and unsubstantiated accusations are taken with large helpings of salt, we will enter a more tolerant society, that concentrates on the expressions rather than the expressor.