Abstract: In a fingerprint matching system, a finger platen formed of an optical element having a tacky reading surface for providing an accurate and consistent image of a fingerprint pattern.

Abstract: A system for matching images in which characteristic points of an image to be tested for a match, such as a fingerprint, are compared with characteristic points of a master image by attempting to match the distances between pairs of master characteristic points with distances between pairs of live characteristic points, whereby the coordinate system of the test image is not required to be aligned with the coordinate system of the master image. The matching system can be implemented in an identification mode in which the live image is attempted to be matched with each of a number of master images, or a verification mode in which the live image is attempted to be matched with a master image that is purported to be the same as the live image.

Abstract: A semiconductor device that functions as a key to control access to a computer or a software program resident in a computer or provides for secure communications is disclosed. The device executes an algorithm that combines a root and a seed to produce a password. The password is input to the computer. The computer uses an equivalent algorithm to produce a password within the computer. Comparison or other methods are employed to allow access to the computer or computer program or to allow for secure communications. The computer can be coded to produce on a video display thereof a time-space stimulus pattern which can be received by sensors of the key. Alternatively, a keypad can be employed to input the stimulus output from the computer into the access key. Further the present system allows for secure communication using algorithms between different computers and between distant locations.