Comparison of classic handwritten signature and electronical signatures with grafological methods

Aim:. With the developing technology in recent years, the use of digital signatures has become widespread, so it can be the subject of investigation and expert examination in the judicial system. In our study, it is aimed to determine whether the signature samples obtained by digital methods are compatible with the classical wet signature habits and which of the parameters used in the conventional evaluation of the signature can be used in an electronic signature. Material and Method: The study is a prospective-experimental study. The study was carried out at Düzce University Faculty of Medicine, Department of Forensic Medicine, Düzce University Research and Application Center. 88 volunteer participants were included in the study. 3 conventional wet signatures were taken on a A4 paper with the dominant hand, 3 signatures on the digital screen with the stylus, and 3 signatures on the digital screen with the index finger without using a device. All samples collected by sitting. Samples evaluated by 2 different forensic document examiner according to graphological criteria, similarities to wet signatures, and criteria used as standard in writing signature examination. Results: Signatures obtained under 3 different conditions; evaluated according to style, direction, size, pen lifts, punctuation, cross draw line and gramma features. There was a statistically significant difference between wet signatures and digital signatures in terms of style, horizontal size, vertical size and proportion characteristics, but no statistically significant difference was found in terms of direction, pen lifts, punctuation, gramma and cross draw line. When the style and size characteristics are compared between the signatures that signed with stylus and finger, it is seen that there are greater discrepancies by finger signatures. Conclusion: It is known that many features that can be detected in a wet signature cannot be detected in digital signatures without special technological methods. In our study, when comparing digital signatures with wet signatures without using additional technological methods, it was determined that the most accurate guiding feature was the style, and there were changes in digital signatures in terms of size characteristics, more so in finger signatures. When a forensic examination of digital signatures is requested, it is thought that the samples of the writing and signatures taken at the court for comparison should be obtained with similar devices and software, also the past candid digital signatures should be obtained from the relevant institutions and organizations and sent to the forensic document examiner. Keywords: Handwriting and Signature Examination, Electronical Signatures, Digital Signatures, Biometric Signatures, Forensic Graphology