A little thought makes it clear that all authentication systems except biometric systems are inherently flawed. Unless there is a biometric test, there simply is no way to ensure that the user is indeed the user. Cards and keys can be lost, stolen, loaned or given to another. UserIDs and passwords can be guessed, socially engineered, or given to another. The only solutions that inalienably bind to the user are biometric systems, e.g., face recognition, signatures, voiceprints, iris scans, fingerprints, DNA matches and the like. And of these solutions, signatures have become easy enough to forge that they no longer can be trusted and in any event are not well suited to e-commerce applications. Considering all the environments in which a trust model must be deployed, e.g., retail locations, online shopping, offices, homes, etc., it becomes apparent that at present really only voiceprints and fingerprints meet the ease of deployment criteria. Deploying cameras to perform accurate facial recognition or iris scans is currently prohibitively expensive or impractical. DNA matching is still a long way from being an unobtrusive process than can occur in a matter of seconds. However a person can record and present a voiceprint simply by speaking into a microphone; a person can record and present a fingerprint by touching a pad on a small USB device. These are intuitive interfaces that everyone understands. While voice prints are an attractive alternative in a private environment, they are not ideal in many environments, for example a noisy supermarket checkout lane or even the typical office cubicle. In addition consumers have to overcome their natural self-consciousness of speaking into a device to obtain authorization.