today's networked world, the need to maintain the
security of information or physical property is becoming both
increasingly important and increasingly difficult. A
fundamental flaw in the conventional access control systems is
that the systems do not grant access by "who we are", but by
"what we have", such as ID cards, keys, passwords, or PIN
numbers. None of these means are really defining us. Recently,
technology became available to allow verification of "true"
individual identi