Palmistry in the 21st century.
In pal, geometry, a camera and an infrared sensor record the shape and proportion of a spread hand. A CCD camera records the hand from above and the system compares features such as the length and width of the fingers with a template. The technical effort is moderate, but the "sensor" is very large compared to a fingerprint sensor.
The hand geometry works quite reliably. The hit rates range between 80 and 95% depending on the system. Apart from the hygienic concerns, the procedure is well accepted by the users. The security for identification and verification is in the middle range. For this reason, palm geometry is usually used in conjunction with an identification card or PIN code.