“…From the literature reviewed, it is noted that there has been significant progress in the off-line signature verification domain. However, despite the progress in the area over the past decades, it remains an open research problem [1,2,23,24]. In addition to the limitations mentioned in Table 1, some general challenges [24] in the area of off-line signature verification that still attract many researchers for further investigation in this field are indicated as follows: i) high intra-class variability in handwritten signatures of every individual compared to the physiological biometrics, such as fingerprints or iris of the individual, ii) low inter-class variability between genuine signatures and skilled forgeries of every individual, iii) the existence of only genuine signatures as partial knowledge for training off-line signature verification systems, iv) limitations in the amount of signature data available for training off-line signature verification systems in real scenarios, as during the enrolment process users often provide only a few samples of their signatures, and v) the presence of signatures written in different scripts.…”