“…In a study by Epp et al [8], besides various time intervals, the number of errors, the number of keystrokes, and the number of characters were also used as the original features, from which the feature subset was selected by the feature selection approach. With some statistical values (e.g., average, equation, skewness, autocorrelation, and moment) and information measurements (e.g., entropy) of the time interval as the features, Ulinskas et al [9] applied a feature selection approach to select a feature subset from them. Based on fuzzy logic, de ru and Eloff [10] divided the time interval into four categories, that is, very short, short, moderately short, and somewhat short, as the characteristics of keystrokes.…”