ABSTRACT
This chapter focuses on synthetic signatures as one of the prominent examples of inverse biometrics. Historically, manually synthesized signatures and forged handwriting have always been a point of concern for handwriting experts and for forensics in general. There are quite a few reports on detecting free-hand forgeries, where a forger makes an attempt to simulate or trace a genuine signature. In the latter case, the forged handwritten object has the proper shape, but differs from a genuine object in the quality and dynamics of the strokes. Free-hand forgeries, on the other hand, differ from a genuine signature with respect to the values of various size and shape features. With recent advances in signature capturing, e.g. low-cost pressure sensitive tablets, handwriting analysis includes another set of features, i.e., kinematic characteristics such as pressure and speed of writing.
