Person Authentication by Handwriting in air using a Biometric Smart Pen Device

The phenomenon of writing reflects developed fine motor skills of a person. Specially, the dynamics of writing can be used for the characterization of the individual writer or written object. Person authentication based on the dynamics of handwriting on pad and in air using biometric Smart Pen (BiSP) device are presented in this paper. We regard hand movement with pen in space as handwriting (or hand gesturing) in air. The acquisition device BiSP is a ballpoint pen equipped with a diversity of sensors, measuring the acceleration and tilt angle of the pen, the grip forces of fingers holding the pen, and the forces and vibrations in the refill during writing, drawing and hand gesturing in air or on any solid pad. For classification, queries and references of multi-dimensional time-series provided by BiSP are matched by fast dynamic time warping DTW. To judge the biometric authentication of a writer, the recognition score rates of PIN words and single characters are computed. It was found that the score rates of performance are better 99.99% and the response time is below 2 seconds for a population of 40 enrolled persons. The proposed handwriting in air is a promising authentication method because performance of writing on paper pad and in air differ marginally. It can create a new dimension of freedom in unconstrained data input, and access control and can compete with the emerging hand gesture recognition methods.