Recognition of living fingers with a sensor based on scattered-light detection

To prevent fraud by use of replicas of human fingers for identity verification, we propose to check variations in color and in a series of previously acquired fingerprint images. Movement of a finger on a human hand induces blood movement, and light scattered inside the finger carries this life-related information. In experiments, we found characteristic changes in color and luminance extracted from the central parts of fingerprint images. Some criteria for recognition of living tissue were tested with input provided by more than 30 participants. Inasmuch as the response of a human body to an external stimulus can be checked by our method with no additional components, this technology can raise the security level of a fingerprint identification system.