Identity is established by finger prints and retinal scans. One more marker is the microbiome of each individual. It is the cloud of microbes or bugs which an individual rains on the surroundings at the rate of a million per hour. An experiment in Portland, USA has validated that a microbiome is specific to individuals. A person not taking antibiotics for months was examined. He sits under controlled conditions — sanitized and climate-controlled chamber. They study the sequenced ribosomal RNA from the cloud of microbes emitted by this healthy person. They also add microbes settled on surfaces in the surroundings. It is a mix of flora. It may constitute a specific marker like a finger print.

Face recognition, finger print recognition and retinal blood vessel pattern recognition are not fool proof as these may be altered by age or life events, say an injury to the thumb or cataract in the eye.

Fool proof authentication does require a mix of identification strategies. Microbiome is an alternative bio-marker. A US company used whorls of ears as a marker. A matrix of weight, anatomy and posture can uniquely identify a driver in an auto seat. Some of the old markers are to be eliminated as these are easy to crack. Multiple genetic patterns could be the Holy Grail of authentication.