This paper presents methods of processing handwritten biometric data. The initial data are coordinates of a position of a pen on a graphics tablet. For this, the proprietary database of handwriting samples and the open signature database SVC 2004 were used. The proprietary database includes 29 users, 754 random and 754 simple forgeries. At the stage of biometric data processing, the following methods were used – «interpolation of handwriting» (entering points at an equal distance between the initial points of the handwritten signature), the histogram approach, «pen movement speed» (the path traveled by the pen at different stages of handwriting input process). Such methods eliminate the variability of the biometric data over time and over spatial axes. As a result, we recommended a standardization approach (Z-score), discretization (one-dimensional linear interpolation and discretization with variable step based on arithmetic progression) of biometric data. The table of results presents the values of the quality of biometric features. The obtained experimental results will be useful for researchers to improve their studies in the field of biometric security systems

Keywords: handwriting, biometric data, graphic tablet, verification, authentication, standardization, discretization, interpolation, information security