Authors: Sharma P, Kumar P, Bhandari D* and Sharma A
Background: In the present study, a metric approach has been made to distinguish between genuine and forged signatures. Certain fixed points were selected and the range of variability between 14 different parameters was calculated. Our study provides mathematics-based corroborative evidence to support the opinion of Forensic Document Examiners. Methodology: For sample collection the samples were obtained in two different sets, in set 1 subject was guided to provide their genuine signature in a continuous running hand fashion and, in set 2, two individuals consisting of a male and a female were asked to forge the sample first by un-practiced hand and then later by the practiced hand i.e. after having practiced and then forge the sample, this exercise was also performed by 50 subjects. Therefore, 500 genuine signatures of 50 subjects were taken, each subject providing 10 samples of their original writing to understand the natural variation, master pattern and range of variability and 200 samples by forging the signature; 100 samples by male subjects and 100 samples by females; inclusive of both practiced and unpractised samples and allotted them a manually calculated mathematical value. This exercise was done for every sample. All the samples belonged to the age range of 20-25 years. Results: The study developed a scientific and reliable method to compare the practiced signature of the individual using a statistical metric deviation-based method. Conclusion: The conclusion showed that forged signatures fail to lie within the limits of the variability of the mathematical parameters taken.
Keywords: Forensic Document Examiner; Signature Verification; Signatures; Fraud; Metric Deviation
