A person may be identified by at least an identification system including a device for capturing an image of a venous network of a finger and a database containing reference venous network images partitioned by class according to topological characteristics and for each class reference topological characteristics. In one embodiment, an image of the venous network is captured, transmitted to the processing unit, centered relative to a display window, and cut into at least two bands parallel to the finger's axis. A set of each band's topological characteristics is extracted. A distance between the extracted set and all reference topological characteristics of the class is calculated, for each class. The venous network image is classified in the class corresponding to the smallest distance and is compared with each reference venous network image in the class. The authenticity of the person from the result of the comparison step is decided.