Thesis - Instituto de Telecomunicações

Chapter 1Introduction1.1 The ProblemOur main research question is centered on finding a subject’s identity based on behavioralrelatedfeatures extracted from some signals dynamics.This question produces relevant challenges for the study of new methodologies in a difficultproblem: how to extract, combine and classify characteristics from behavioral sourcesto distinguish a large number of classes?Our focus in this problem is the introduction of new behavioral biometrics traits. We detainedour attention on some time varying signals, collected from the human being, to assertthe possibility of having biometric identification capability. With this goal, we elected andcollected a set of dynamic signals, observed their physiological manifestation and their morphology,and prepared robust signal processing algorithms, capable of extracting relevantcharacteristics.The selected signals were based on the human-computer interaction (HCI) (via a mousedevice), the Electrocardiography (ECG) (the electrical signal that controls our heart), andthe Electrodermal Activity (EDA) (the controlling signal of the sweat in our hands andbody). Examples of these signals collected from 10 different individuals, and used forbiometric classification, are presented in: figure 1.1 - the HCI signals; figure 1.2 - the ECGsignal; and figure 1.3 -the EDA signal. These figures provide a glance into the nature anddifficulty of the problem of human identification based on these signals.1