How many user-ids do you have? Passwords? The answer may depend on the number of accounts you hold on various internet sites. We are told not to select the same userid and password, but my goodness - who can remember them all? Hackers get smarter and slicker year after year, being able to trick computer systems into thinking that they are, in fact, the user logging in.

Will the technologies of biometric identification solve these issues in the future? In other words, will our unique fingerprints, retinal scans and the like protect us and allow us the freedom of never having to create and remember unique ways of identifying ourselves online? Biometric identification may also free us from our key chains, allowing us to enter our homes, cars, safes, and other secure locations with the scan of a fingerprint or retina. Its not fictional stuff anymore. The future is here!

But is there a downside to this so-called freedom? Are we actually sacrificing our privacy? Some would say yes, indeed. And its already happening. Countries around the world are requiring biometric identification authentication for passports, identification cards, and in banking systems (Japan, United States, Germany, Australia, Israel, Iraq, Nigeria and Brazil, among others).

In general, "biometrics" is a statistical analysis of certain human biological or physiological traits, such as fingerprints, signature style, voice, irises, so as to uniquely identify and distinguish people from each other. As stated in Wikipedia, various biometric identfication technologies are compared as follows:

• Uniqueness is how well the biometric separates individually from another.
• Permanence measures how well a biometric resists aging.
• Collectability ease of acquisition for measurement.
• Performance accuracy, speed, and robustness of technology used.
• Acceptability degree of approval of a technology.
• Circumvention ease of use of a substitute.

Obviously, some of the most accurate biometric technologies include DNA analysis. Less accurate would be examining signatures. Some of the new technologies in development may result in identification by gait (the way a person walks), ear canal analysis, and odor!

Some concerns have been raised about people stealing fingerprint identities (for example) and compromising a biometric identification system. After all, unlike a lost PIN or password, a fingerprint cannot be re-issued. Proponents of biometric identification technologies note, however, that it is very unlikely to occur.

In general, these are the best biometric identification techniques. With the possible exception of face recognition, the characteristics analyzed do not change over a person's lifetime:

1. Face recognition: Easy to do, even when the subject does not know his or her face is being scanned. Privacy concerns, of course.
2. Fingerprints: A gold-standard for over 100 years. Even identical twins do not share the same finger prints. Minor concerns arise if hands are not clean.
3. Retinal scan: Examines the pattern of blood vessels at the back of the eye, which are unique to each person. Takes at least 15 seconds to complete. No way to run this test without the subject knowing.
4. Iris scan: Similar to retinal scan; information does not change over the person's lifetime.
5. Hand geometry: Much like face recognition, this is easy to do and non-intrusive. Subjects place their hand on a slate for analysis of distances between fingers, thickness of palm base, etc. Clean hands not required.

There are still some kinks being worked out so that biometric identification technologies can work accurately and consistently. For example, fingerprint scanners may malfunction if the person's tips are dirty, resulting in a poor scan. Eye scans are not intuitively used, and can result in extra time, inaccurate results, and also some discomfort from the light shined into the eye. Facial recognition is still in development; some systems can be fooled by hats or facial hair. Ultimately, scientists expect it to be better in a few years. But that still doesn't address invasion of privacy concerns.

Its safe to say that we're in for a James Bond-esque future with biometric identification. Cool gadgets will literally be at our fingertips. There is much to be learned and fine-tuned, but someday soon you may be able to kiss your thick wallet and key chain goodbye.