Abstract: A method and apparatus for performing personal identification and/or verification at perdetermined stations or checkpoints is provided. Each person to be identified has a unit such as a card, badge or other token or device which stores a predetermined coded value, at least a predetermined portion of which is changed at selected time intervals in accordance with an algorithm, the algorithm being such that the value of the predetermined portion of the stored coded value at any given time is nonpredictable. The unit has a triggering signal generator, the unit being responsive to the triggering signal to present an indication of the current stored coded value to the station, the station responding to the predetermined coded value for identifying the person. Triggering may be in response to detection of a predetermined beacon from the station, in response to a user keypad input or may be periodically generated.