Abstract: A method and apparatus is disclosed for verifying whether a particular individual is a member of a predetermined group of authorized individuals. The subject apparatus is particularly suited for controlling access to a secure resource such as a computer network or data base. In accordance with the subject invention, time delays are measured between successive strokes of a keyboard as the individual enters his name. A timing vector, which is constructed from the time delays, is statistically compared with a stored timing vector derived from the authorized individual. If the timing vectors are statistically similar, the individual will be permitted access to the resource.