Dynamic signatures: A review of dynamic feature variation and forensic methodology

Abstract

This article focuses on dynamic signatures and their features. It provides a detailed and critical review of dynamic feature variations and circumstantial parameters affecting dynamic signatures. The state of the art summarizes available knowledge, meant to assist the forensic practitioner in cases presenting extraordinary writing conditions. The studied parameters include hardware-related issues, aging and the influence of time, as well as physical and mental states of the writer. Some parameters, such as drug and alcohol abuse or medication, have very strong effects on handwriting and signature dynamics. Other conditions such as the writer's posture and fatigue have been found to affect feature variation less severely. The need for further research about the influence of these parameters, as well as handwriting dynamics in general is highlighted. These factors are relevant to the examiner in the assessment of the probative value of the reported features. Additionally, methodology for forensic examination of dynamic signatures is discussed. Available methodology and procedures are reviewed, while pointing out major technical and methodological advances in the field of forensic handwriting examination. The need for sharing the best practice manuals, standard operating procedures and methodologies to favor further progress is accentuated.

The potential of collaborative learning as a tool for forensic students: Application to signature examination

“…Results were presented and discussed within the classroom (activities 3, 4 and 5). Further theoretical concepts included explanations of the neurological basis for handwriting, the potential of linguistics in questioned document examination and the examination of digitally captured signatures [22][23][24][25]. Moreover, several questioned document examiners recounted their experiences through several casework examples, including typical issues encountered in practice (e.g.…”

Online Signature Verification Using Single-Template Matching Through Locally and Globally Weighted Dynamic Time Warping

“…In fact, FDEs typically analyze writing variations that provide an important indicator for writer characterization [4], [5]. Particularly, local stable parts in a signature prevent forgers from imitating it perfectly [5], [13].…”

“…These studies addressed the limitations of the single-template strategy. However, this approach still has room in terms of performance improvement in real scenarios, such as forensic document examiners (FDEs) that need to investigate various types of signatures obtained under different writing conditions [4], [5].…”

Template Matching Using Time-Series Averaging and DTW With Dependent Warping for Online Signature Verification

“…In forensics, a signature has been generally examined by FDEs via consideration of its different characteristics in different writers with different writing conditions [13], [14]. In biometrics, better performance has been demonstrated through the use of writer-dependent features and threshold, as compared to the use of a common threshold [44], [45].…”

“…On one hand, signature verification in biometrics enables the authentication of writers with respect to their behavioral characteristics in security situations (e.g., border control, financial fraud, and cyber security) [1]- [7]. On the other hand, automated signature verification methods in forensics support forensic document examiners (FDEs) in performing their work efficiently [8]- [14].…”