I'm still on my quest to find good user authentication techniques that can supplement or replace the old username and password scheme. In this age of spoofing, phishing and stolen IDs, we need strong multifactor authentication to make sure that a user is who he says he is, and an application is the genuine thing. It's especially important for Web based applications like online banking and other applications involving financial transactions.

I've come across a company with a truly unique authentication technique. Passfaces Corporation provides authentication based on the recognition of faces. Scientific studies show that people have the innate ability to recognize familiar faces long after we have been exposed to them. This technology, then, uses a set of faces instead of the usual numbers or letters in passwords and PINs as a secret authentication code.

Here's how it works. An individual is assigned a set of five faces. He is given an orientation session (usually lasting two to four minutes) to imprint those faces into his brain. Studies have shown that a person can recognize a distinct face years after first exposure to that face.

In using Passfaces to authenticate an application, the user is presented with a grid of nine faces. Only one face on the grid is from the user's unique set of faces; the rest are decoys. He must select his specific face on the grid to get passed the digital gate. This process continues for the other four faces of his set. If he fails to recognize or select all of his faces, he is taken back a step to try again. If too many failures occur, he is locked out of the application.

Try it for yourself. Passfaces has an online demonstration of the technology.

Now let's look a bit at the science behind Passfaces. This unique technology is supported by extensive academic studies and experiments.

Professor Hadyn Ellis of the School of Psychology at the University of Wales in Cardiff studied how the human visual brain works and how it perceives, remembers and recognizes faces. He concluded that face recognition is a dedicated process that is different from general object recognition. Both inference and direct neurological measurement indicate that our brains have a special component whose sole function is to recognize faces. What's more, the human brain commits faces to memory without any conscious effort, and familiar faces are recognized, not recalled.

Linda Musthaler is a principal analyst with Essential Solutions Corporation.