Palm print
Palm prints have been in use for over a century as a means of identification. Many of the methodologies used in fingerprint identification have now been adapted to palm prints. A palm print is essentially the large inner surface of the hand. It possesses certain discernible and unique characteristics, which can be easily extricated using Palm print Capture Devices.

These devices provide an image called a friction ridge impression. The impression can then be checked for the unique characteristics which include principal lines, ridges, minutiae points, singular points and texture.

A palm print is a physical feature that remains unaltered for the entire lifespan of an individual, much like a fingerprint. The adoption of palm prints in biometrics has been slower because palm recognition involves using larger images and more complex algorithms, thus causing constraints in computing capabilities and live-scan technologies.
An Evaluation of Palm Print Recognition Techniques using DCT, Haar Transform and DCT Wavelets and their Performance with Fractional Coefficients

Advantages:
  • Except for size, the pattern is permanent from the 18th week of embryonic development
  • Is effective even with low resolution images
  • Low intrusion for both acquisition and authentication
  • Acquisition devices are low-cost
  • Besides the ridges (which are the same as those used fingerprint matching), the principal lines can also be used
  • The hand shape makes identification of the hand (whether left or right) and orientation.

Disadvantages
  • The FRR and FAR has higher than other biometrics such as fingerprints, iris, retina and DNA
  • Matching to large databases is slower than for fingerprints
  • Unless authentication is contactless, the potential exists that forgers can copy the image from the sensor.

More at:
A study of brute-force break-ins of a palmprint verification system
A Survey Paper on Palm Prints Based Biometric Authentication System
An Evaluation of Palm Print Recognition Techniques using DCT, Haar Transform and DCT Wavelets and their Performance with Fractional Coefficients
Palmprint Feature Extraction Using 2-D Gabor Filters
Palm Print Recognition
Touch-less palm print biometrics: Novel design and implementation