What is more basic -- the numbers 1,2,3... or the shapes: lines, curves? What comes first, algebra or geometry? One thing is for sure, human beings capture shapes faster, and more permanently than they capture a long series of digits. So, if we could translate, say, a phone number to, say, a 'happy face' then we would remember the facial expression better than we would remember the phone number. Only that there is a problem there. Suppose we remember the face very well, but forgot the number -- we cannot 'dial' the face, can we?

So to dial that phone number we would have to suggest different numbers the best we remember, then translate each suggested number to its corresponding shape. When we finally hit the right number, we will know it, because it would figure out as the happy face that we remember all too well.

This is the principle of a very interesting and useful concept in computer science. We can verify a number that we don't know -- only know its corresponding shape. And knowing that shape does not help us regenerate the number.

The PINpen concept offers a remarkable new paradigm in man-machine interface (MMI). Computers are good with numbers but a little clumsy with shapes. People are good with shapes but a bit overwhelmed with long winding numbers. Take the strong point of each partner (man vs. machine), and figure out procedures to do things that were not doable beforehand.

And that's exactly what we did. Check this partial list of practical applications.

Combating Identity Theft in Cyberspace: You get a PIN from your bank, but you never type it in to your computer. Instead you select a graphic shape from a line-up. The bank verifies that it talks to you, while you verify that you are talking to the bank: mutual authentication of identity!

Combating Identity Theft in the Physical World: Personal cards may be stamped with a graphic shape that corresponds to the secret PIN issued to the card holder. When used, the examiner would ask the bearer of the card to punch into his cellphone (or any cellphone) his secret PIN. The built-in PINpen algorithm would produce the corresponding graphics. If it fits the shape embossed on the card, then the bearer of the card is not an identity thief, but the rightful owner.

Anti-Theft Label: Expensive items (e.g. Rolex Watches) may be etched with the PINpen graphics that corresponds to a secret ownership number known only to the rightful owner. A thief, trying to sell a stolen watch like that would not be able to re-produce the marked graphics by punching the secret PIN into his cellphone (or into any handy computer where the PINpen software is installed).

PINpen Lottery: Online gaming is big business, based on pseudo-random number generation, which is easy to tweak. Players are never sure that the game owner is not 'cooking' the results. With PINpen the owner can choose a winning number, publish the corresponding shape, and then he cannot change his mind because any proclaimed different winning number would generate a different shape.