One problem with biometric identification is that the device reading data (fingerprints, eye "prints", etc.) from the person has to be trusted by the entity dec

One problem with biometric identification is that the device reading data (fingerprints, eye "prints", etc.) from the person has to be trusted by the entity deciding the legitimacy of the user. If I have a digital copy of your fingerprints and I "own" the fingerprint reader trusted by your bank/whatever, I can pretend to be you. Given that people generally own the phones they use, I wonder if this barrier to fraud is any less expensive or more effective than existing security schemes. For example, have something/know something methods (RSA random number generator keychain dongles coupled with a known passcode) that are much easier to implement and don't rely on network effects -- For people to buy earprint phones, they have to be commonly used as a form of auth, but enough people must own them for banks, etc. to consider such a scheme. Business idea: A problem with the RSA dongle thingy is that a person would have to carry one for EVERY entity with which he authenticates himself. I'm sure some sysadmins already have a pocket full of this things. What if there was a 3rd party that would offer have something/known something authen services? Or, more generally, authen services with a variety of security levels? Then, a person would just carry around his "Windows Live" dongle and could authenticate with all his banks, etc. Not a good startup idea as it takes a powerful entity to surmount network effects, but it would solve a real problem for real people.